Lower City Sewers

View of the northern section of the Lower City Sewers

Undercity
Undercity Ruins
↑
Abandoned Cistern	←	Lower City Sewers	→	Cazador's Dungeon
↓
Guildhall

The Lower City Sewers is a Location within the Undercity in Act Three of Baldur's Gate 3.

“

I'll brave a lot of things, but I'd rather not wade through the city's waste water, thank you.

„

— Shadowheart, on the Lower City Sewers

Overview

Map of the Lower City Sewers, north of it are the Undercity Ruins

The Lower City Sewers is a large expansive area covering much of the Undercity. It also serves as the main access point into nearby Undercity Ruins.

The boundaries of the Sewers are ambiguous because several areas share a similar aesthetic, but are marked as separate locations, namely the Abandoned Cistern and the Guildhall. See the correspondent pages for more detailed descriptions of the two noted locations.

The names of other subsections are reference designations derived from the notable characters and / or objects encountered in any particular area. For clarity, this article distinguishes between areas based on their geographical situation according to cardinal directions, with some of them having conventional borders.

Historically a tribe of gutter kobolds was contracted to maintain free flow in the sanitation tunnels, but as of late they appear to have been slain or driven away by forces or circumstances unknown.

The sewers can be accessed through numerous manhole covers on the surface, and connects to almost every other location of the Undercity except the Murder Tribunal.

Entrances

There are several points from which the sewers can be entered. Most are outside somewhere in the Lower City and a few are from indoor locations.

Entrance	General Area	Location Sewers	Location Outside	Access from Outside
Dripping Pipe	Eastern Tunnels	X: 27 Y: 822	X: -1262 Y: 740 Heapside Prison	Through the Manhole located in Heapside Prison
Ladder	Eastern Tunnels	X: 46 Y: 780	X: 128 Y: -30 Lower City	Through the Manhole located between Stormshore Tabernacle and Basilisk Gate Barracks
Ladder	Sarin's Funeral	X: -82 Y: 843	X: -161 Y: -61 Lower City	Through the Manhole located in front of Golbraith's Cellar
Ladder	Eastern Tunnels	X: 52 Y: 793	X: -753 Y: 592 Knights of the Shield Hideout	Through the Hatch located in the Knights of the Shield Hideout in the basement of the Elfsong Tavern
Ladder	Abandoned Cistern	X: -283 Y: 879	X: -251 Y: -87 Lower City	Through the Ornate Wooden Hatch located in the Gardener's Basement through the wooden door labeled as "Keep Out"
A greasy, smelly climb up	Treasure Room	X: -158 Y: 835	X: -1097 Y: 335 Flymm Cargo	Through A greasy, smelly climb down located in the basement of Flymm Cargo
Gloomy Descent	Sewage Raft	X: -111 Y: 886	X: -1981 Y: 843 Cazador's Dungeon	Through Gloomy Ascent after unlocking a Crypt Gate in Cazador's Dungeon - cannot be entered from the sewers side until used from the dungeon side
No Entry - No Exit door	Guildhall	X: -14 Y: 772	X: -14 Y: 772 Lower City Sewers	Through the headquarters of the Guild, behind the bar
Hidden door	Secret Sewer Vault	X: -60 Y: 784	X: -60 Y: 784 Lower City Sewers	Through the hallway next to the Secret Sewer Vault which can be accessed from  Nine-Fingers Keene's bedroom - cannot be entered from the sewers side until opened

In addition to this list, the iron grate in the lowest corner of the Beehive General Goods' basement was reported to be interactable in earlier versions of the game, presumably providing an additional entrance to the Lower City Sewers. This was discarded by the current version of the game.

Main system locations

The sewers are a vast network of tunnels and rooms which connect several places within Baldur's Gate. A subdivision is made of area's of interest inside the sewers.

Eastern Tunnels

Eastern tunnels of the sewers

The eastern tunnels of the sewers can be entered from Lower City in three ways, all located in the Eastway district of the city:

• Descending through the pit latrine in the Heapside Prison
• Climbing down a hatch in the Knights of the Shield Hideout
• Climbing down a manhole located in an alley between Stormshore Tabernacle and Basilisk Gate Barracks

The descent from the prison leads into a cavern with a wall breach to the sewers, with nothing remarkable inside.

The entrance connected to the Knights of the Shield Hideout leads to a small storeroom. Numerous Traveller's Chests on the shelves at X: 56 Y: 796, as well as Wooden Chest in the opposite corner, contain gold, random Valuables, potions and / or spell scrolls up to Very rare grade. In the southwestern corner is a table with a journal describing  Duke Stelmane's ongoing illness before her murder. The Stack of Books near the table contains two books concerning Mind Flayers, and on the bench nearby is a  Scroll of Detect Thoughts.

The entrance from the manhole initially leads to a room without an exit, but a wall at X: 39 Y: 783 is highlighted with a  DC 15 Perception Check and can be destroyed. In the room behind it a stairway leads to an entrance to the Guildhall. A wall breach in this room allows access to the main sewer system.

All three outside entrances end up at the same tunnel with the middle part filled with  Noxious Fumes emitting from four vents on the ground. A lever on the southern wall disables them (can be triggered with a  Ranged Attack). The fumes hide shelves with a locked Rustic Chest (requires  DC 15 Sleight of Hand Check), which contains random wines.

The door at X: 6 Y: 800 opens into the next part of the tunnels. Here cultists of  Bhaal idle time, using several refugees as living dummies for shooting. If the party have made a deal with  Orin (see Involvement section below), they are not immediately hostile, and the party can choose to join in, side with the refugees, or ignore them.

In the middle of this room are several vents with a Noxious Fumes trap. It triggers when weight is applied to a Granitic Rock at X: -22 Y: 805 and is disabled with a lever at X: -35 Y: 805.

If the party choose to stand up to the refugees and defeat the cultists, the refugees flee through the doors at X: -42 Y: 789 to the next hallway. Unless disarmed prior, three Tripwires planted there trigger explosions which kill the refugees. Each trap requires  DC 17 Perception Check and  DC 15 Sleight of Hand Check to spot and disarm.

At X: -60 Y: 784 in this hallway is a hidden door leading into  Nine-Fingers Keene's vault, accessible from her bedroom. This door can only be opened from the other side. Opposite the hidden door is a short pier where the sewage raft can dock.

Continuing the path further west leads to another locked door ( DC 15 Sleight of Hand Check to lockpick) which opens into the main sewer area. The  City Sewers waypoint is nearby at X: -98 Y: 779.

Arabella's Cave

Cave area where Arabella is

To the west of the waypoint an improvised bridge leads up to a natural cave where  Arabella stands if she survived to Act Three. She is staring intently at a stone and offers the interacting party member do the same. A successful  DC 15 Arcana Check, or  reading Arabella's thoughts, allows them to learn that the stone is magical, and has absorbed many lifetimes of stories from the city above. Arabella is now absorbing them too.

The party can catch up with Arabella, and also ask her about the dead bodies strewn around her – the thugs ( Brigand Harrold,  Livin' Large Timbo,  Woodchips Grant, and  Ogreboy Colum) who attempted to attack her. Talking to Arabella (regardless of the roll result) updates the ⁠Gather Your Allies quest.

On the way to Arabella at X: -127 Y: 772, a  DC 15 Survival Check reveals a buried treasure chest with gold, Valuables and random Very rare spell scroll.

To the north of Arabella's cave the ground is covered in  Grease and  Oil. A Traveller's Chest on the ground contains alchemical ingredients and a  note revealing their illegal provenance. Further north is another makeshift bridge which leads back to the main sewer area.

Sewage Raft

Traversal area of the raft

One of the sewers' gutters has a raft line which can be used to travel north and south. The small wooden raft moving along it has two levers, each indicating to which side it will move. The raft moves between three piers, passing them one at a time (its initial position is at the middle pier). Levers on the piers (on the nearby wall for the southern pier) work as call buttons for the raft.

• The southern pier at X: -60 Y: 796 is adjacent to the Eastern Tunnels, the door connecing to it with the main part of the sewers is locked (requires  DC 15 Sleight of Hand Check to lockpick).
• The middle pier X: -66 Y: 827 is by the locked door to the  mad sorcerer's asylum (see below) ( DC 10 Sleight of Hand Check). To the north of the door is a ladder leading up to the manhole near Golbraith's Cellar.
• The northern pier at X: -78 Y: 827 meets the end of the raft line. A locked door near it leads to the Gloomy Descent – the subterranean entrance to the Cazador's Dungeon, which can only be opened from inside the dungeon itself.

Use of the sewage raft together with careful movement (i.e., hiding or entering Turn based mode) allow the party to walk around the middle part of the sewers, where a mad sorcerer resides, without triggering an encounter with him.

Mad sorcerer's lair

Area where Aelis Siryasius is having a funeral for his friend

The middle part of the sewers ground is partly covered in  Grease, and several dead Absolute Cultists lie around. One of the corpses carries a  note mentioning a "mad wizard". If the party approach him dialogue is triggered.

 Aelis Siryasius, however, is not a wizard, but a sorcerer of a Draconic Bloodline. He accuses the party of working with the Cult of the Absolute and of interrupting the funeral he is holding for someone named Sarin. He becomes hostile if not discouraged from conflict.

Placating Aelis requires various ability checks; if successful, Aelis allows safe passage through his lair. However, speaking with him again or re-entering this part of sewers still turns him hostile. A full list of available ability checks is on Aelis's page.

In the middle of Aelis' lair is a red-outlined, locked Grated Iron Door which can be unlocked with a  Key carried by Aelis. Behind the gate is a Wooden Chest containing  Scorched Book, gems, alchemical ingredients, and gold.

Multiple  Grease Mephits and  Greaseballs patrol Aelis's lair, along with two  Grease Elementals he calls 'cousins'. They all side with Aelis if the party confront him. However, it is possible to reduce the number of possible enemies by carefully picking off the Mephits and Grease Balls which patrol a large area around. The ground in this area is partly covered with  Grease. It can impede the party's movement and be ignited with any ⁠⁠Fire spell. If this happens during a fight, the Grease Mephits can then summon  Magma Mephits instead of new Grease mephits using their class action.

The hall with doors leading to Undercity Ruins

To the north of the lair at X: -146 Y: 864 is a room where four Loose Stones can be spotted with successful ability checks:

• One check is always successful at X: -146 Y: 902
•  DC 10 Perception Check at X: -131 Y: 880
•  DC 15 Perception Check at X: -133 Y: 894
•  DC 20 Perception Check at X: -131 Y: 880

Minor loot is hidden under each stone, except the last one, which contains a  Painted Key used to unlock a nearby Painted Chest. Otherwise, the chest can be lockpicked with a  DC 20 Sleight of Hand Check. Inside is gold, a random common armour, and possibly random arrows (Rare or Uncommon) or a random spell scroll (Very rare).

Several documents are around the room (including stashes under loose stones):  Incomplete Journal,  Torn Journal Fragment, and  Stained Journal Fragment provide background story on  Sarin and her companions. A backpack in the northwest corner contains a note titled  You've Got Friends in the Guild.

Going further north brings the party to the entry way towards the Undercity Ruins and its related  Undercity Ruins waypoint. The party can also travel west towards the treasure room and further to the Abandoned Cistern.

Treasure Room

Treasure room underneath Flymm Cargo

The treasure room is a large open area which features a large pipe which goes straight through the room and ends at an entry point for the sewers. Atop the slippery hill at the end of the pipe is a passageway called A greasy, smelly climb up... which links the sewers to the basement of Flymm Cargo.

On a piece of land surrounded by flowing sewage  Dairow Vin lies unconscious. Grieving the loss and probable death of his husband, Dairow consumed a large quantity of  Potions of Sleep, falling into an  impenetrable slumber. His backpack contains one last Potion, a set of  Thieves' Tools, and a note with a proposal on joining the Guild.

A  Kobold Thief is on the other side of the pipe at X: -171 Y: 854. He carries a map of the sewers which references  Bugthimble and some tribe treasure. Upon reading the map, a marker is added to the minimap called Cache indicating one of the five surrounding Dirt Mounds. After digging up the chest, a successful  DC 25 Perception Check reveals the trap. If detected, the trap requires  DC 15 Sleight of Hand Check to disarm. However, triggering a trap does no harm except pushing the party members 3m away from the chest. Each of the five dirt mounds reveals a similarly trapped, locked chest ( DC 7 Sleight of Hand Check to lockpick) with one of the following notes:

•  Scrawled Note (Sewers, crown)
•  Scrawled Note (Sewers, gem)
•  Scrawled Note (Sewers, sword)
•  Scrawled Note (Sewers, coin)

The actual treasure is in the northernmost dirt mound at X: -178 Y: 862. From it the Marked Chest: Dragon (trapped as well) emerges, which requires a  DC 20 Sleight of Hand Check to lockpick. It contains gold and random Valuables.

Following the large pipe in this room leads to the Abandoned Cistern. The cistern can also be accessed by going through a broken gate inside the streaming sewage on the west.

Specific Adjacent locations

Abandoned Cistern

Abandoned Cistern west of the sewers

Main Article: Abandoned Cistern

The Abandoned Cistern lies underneath Baldur's Gate and is part of its Undercity. It is the westernmost part of the Lower City Sewers and shares similar aesthetics. It serves as mud-setting pit for the sewer filth, separated from the other drainage by a system of sluice gates and valves.

The area is divided into two rooms; the eastern one with the large pipe is guarded by a group of Bhaalist cultists. Unlocking the westernmost requires solving a puzzle or passing a  DC 25 Athletics Check on a valve at X: -197 Y: 867. A similar valve inside can also open the way via the same check. Once opened, the door can serve as another entrance to the sewer system through the Gardener's Basement, part of Lady Jannath's Estate.

During the game the Abandoned Cistern serves as a hideout for the leader of a newly-sprung bandit gang, who goes by the name of the  Stone Lord. Tadpoled and suborned into obedience by agents of the Cult of the Absolute, he had been rather successfully rooting out other lesser gangs loyal to Thieves' Guild. Following his track eventually leads the party to the Abandoned Cistern, where the connection between the cult and the mercenary and smuggling organization, the  Zhentarim, becomes clear.

Guildhall

Guildhall south of the sewers

Main Article: Guildhall

The Guildhall is the underground headquarters of  The Guild – the main criminal syndicate in Baldur’s Gate and the city suburbs. It is a joint management centre for disparate local gangs and solitary dealers, as well as a social space with merchants dealing in "pre-owned stuff", illicit goods, services and leisures, and trading information.

During the game's events, the Guild (and by extension the Guildhall) is run by the Guildmaster  Nine-Fingers Keene. As of late the Guild's positions have been substantively undermined by the actions of the  Stone Lord's gang. To regain turf, Nine-Fingers struck a deal with the  Zhentarim, a trading and mercenary organization with back-alley morals. She does not know that the Zhentarim are planning to use this contract to dethrone the Guild itself and take its place in Baldur's Gate.

There are two places where the Guildhall connects to the Lower City Sewers.

• A locked door called No Entry - No Exit at X: -14 Y: 772 leads to the back of the bar. It requires a  DC 20 Sleight of Hand Check to lockpick or can be opened with the  Severn's Sewer Key carried by  Severn the bartender.
• A hidden door which can only be opened from inside the Guildhall near the Secret Sewer Vault.

Once opened, either of these entrances can serve as an additional access point to the Lower City Sewers through the Guildhall entrance in the back alleys of the Brampton district of Baldur's Gate.

Undercity Ruins

Main Article: Undercity Ruins

Undercity Ruins is the northernmost part of the vast Undercity beneath the streets of Baldur's Gate. It can only be accessed through the Lower City Sewers, where at approximately X: -138 Y: 907 the minimap location changes to "Undercity Ruins" after walking north through a stone archway, and the  Undercity Ruins waypoint is activated

The Undercity Ruins holds the darkest secrets of Baldur's Gate: the Ancient Lair of a powerful  mummy lord, the temple to the God of Murder,  Bhaal, preceded by catacombs, and the Morphic Pool, where the final events of the game unfold.

To the west at X: -180 Y: 935 is a passageway which leads to the Ancient Lair. Aside it stands  Voiceless Penitent Bareki who has some items and alchemical ingredients for sale. Behind him is a pouch containing  Sarin's Skull, which is needed to bring peace to  Sarin (see Involvement section below.

Involvement

Eastern sewer tunnels
(by Martijn Petersen)

“

– What's the name of that river down there?
– Wizard called it the Soo-Errr.
– Whatever it's called, it's impressive. And it tastes great.

„

— Grease Mephits summoned by Aelis, bickering

The Lower City Sewers is a location where several major quests can be started and / or updated. Also, there are lesser encounters which show the hidden life of the city's Underbelly and generally add flavour to the playthrough. The encounters which take place in separate sublocations of the Undercity like Abandoned Cistern, the Guildhall or Undercity Ruins, are not listed here.

Encounter with Orin

If  Orin's kidnapping as part of ⁠Rescue Orin's Victim is not started with a long rest, it can also be triggered in the Lower City Sewers in two places: when the party access the sewers from the Knights of the Shield Hideout, or in the area close to the Undercity Ruins waypoint at X: -141 Y: 923.

In this case, the event is mostly the same for each person – Orin approaches the party disguised as any of their companions she has abducted. The kidnapped victim appears grievously injured and begs the party to run away, explaining how they were brutally tortured by Orin. Regardless of the answer, Orin reveals herself and her kidnapping plot. She demands the party kill  Gortash in exchange for the abductee's life. The party can agree to her conditions or refuse; though at this point the decision bears only minor consequences.

Encounter with Kith'rak Voss

Depending on the state of ⁠Help Kith'rak Voss quest,  Voss may stand near the middle pier of the sewage raft along with his friend and mount  Qudenos in the form of a red dragonborn. If the party have the  Orphic Hammer, they can show it to Voss to be awarded with the  Silver Sword of the Astral Plane (if it was not obtained earlier). Interacting with Voss updates all quests concerning  Prince Orpheus and  Lae'zel's personal quests (whether companion or origin), as well as ⁠Gather Your Allies quest.

The party can also speak to Qudenos and pass a  DC 15 Insight Check to discern he is a true dragon. Githyanki and Dragonborn characters have additional dialogue options.

If the party attack either of them, both try to teleport away on their first turn, even if restrained, silenced, or incapacitated. However, both can still be killed within that single turn. In this case, the sword can be looted from Voss.

Encounter with Gandrel

If  Gandrel survives Act One, and  Astarion's personal quest (either ⁠origin or ⁠companion) or the ⁠Investigate Cazador's Palace quest was resolved by freeing the captured vampire spawn, Gandrel shows up near the Lower City Sewers waypoint with his children  Chessa and  Kass.

Strange date in the sewers

On the northern pier of the sewage raft stands  Lorna Esthelian. She is waiting for her date to take her to the 'palace' (likely Szarr Palace), though she feels uneasy about rather specific meeting place they have appointed. Throughout the dialogue she blurts out details which suggest her date is a vampire. The party can enlighten her or keep it a secret. Regardless, she changes her mind and leaves, disappearing from the game.

If  Astarion (as a companion) is present, the dialogue with Lorna slightly changes, and he himself can chime in. The encounter with Lorna does not change even if the party have already explored Szarr Palace.

The area around the pier is littered with broken mirrors, various silverware and missing child posters, all referencing the children of the Gur tribe abducted by Astarion on  Cazador's orders. The bronze-wrought grates which separate the approach to the Gloomy Descent from the sewers bear the aesthetics of Cazador's Dungeon and are adorned with same malachite panels as in the Szarr Palace. Numerous containers are around, including an Opulent chest; they contain no precious items.

Sarin's Funeral

In the middle of Aelis Siryasius' lair is a coffin with a headless glowing skeleton inside. The skeleton has an interactable slot to reattach  Sarin's Skull. The skull itself is in the red-outlined pouch guarded by the third member of Sarin's gang,  Voiceless Penitent Bareki, who is near the beginning of the Undercity Ruins. After the skull is obtained, a Headless Ghost starts following the party member who keeps it in their inventory (they comment on this). The ghost has its own hit points, but cannot be interacted with and disappears should the party engage in a fight or leave the sewers for the surface. It is not shown as an attached party follower.

Combining the skull and the skeleton itself does not make Aelis (if still alive) hostile. Once the skull is returned to the skeleton, Sarin's ghost appears again (now with her head in its place), bows and rewards the party with  Chancer's Carcanet. Her skeleton stops glowing and is renamed Sarin at Peace.

Waypoints

This location contains the following Waypoints

•  City Sewers at X: -98 Y: 779
•  Undercity Ruins at X: -141 Y: 941

Related locations

• ⁠Abandoned Cistern
• ⁠Cazador's Dungeon
• ⁠Flymm Cargo
• ⁠Guildhall
• ⁠Guildhall Entrance
• ⁠Knights of the Shield Hideout
• ⁠Lower City
• ⁠Undercity Ruins

Related quests

• ⁠Aid the Underduke
• ⁠Free Orpheus
• ⁠Help Kith'rak Voss
• ⁠Gather Your Allies
• ⁠Get Orin's Netherstone
  • ⁠Rescue Orin's Victim
• ⁠Return Rakath's Gold
• ⁠The High Harper

Characters

Characters located in the Guildhall and in the Abandoned Cistern are listed on the correspondent location pages.

Notable

•  Aelis Siryasius
•  Arabella - conventional
•  Kith'rak Voss - conventional
•  Orin
•  Qudenos - conventional, in his Dragonborn form
•  Sarin

Bhaal Cultists

•  Blythe
•  Dogaletto
•  Kryss
•  Phylle

Other

•  Brigand Harrold - deceased
•  Chessa
•  Dairow Vin
•  Gandrel
•  Kass
•  Livin' Large Timbo - deceased
•  Lorna Esthelian
•  Ogreboy Colum - deceased
•  Refugee Khathi
•  Refugee Pharbz
•  Refugee Sconnor
•  Woodchips Grant - deceased

Creatures

•  Cranium Rat - 3x
•  Greaseball - 9x
•  Grease Elemental - 2x
•  Grease Mephit - 9x
•  Kobold Thief - deceased
•  Magma Mephit - possibly summoned

Loot

• Chancer's Carcanet
• Cindermoth Cloak
• Quarterstaff +2

Related literature

• Broom and Bucket
• Capture Orders
• Curled Missing Poster
• Creased Missing Poster
• Damp Missing Poster
• Faded Missing Poster
• Incomplete Journal
• Map to Bhaal Temple
• Map of the Sewers
• Municipal Sanitation Notice
• Notes on Mind Flayer Anatomy
• On Psionic Manipulations and Countermeasures
• Our Offer Remains Open
• Parchment (Lower City Sewers)
• Patient Log: Duke Belynne Stelmane
• Scorched Book
• Scrawled Note (Sewers, crown)
• Scrawled Note (Sewers, gem)
• Scrawled Note (Sewers, sword)
• Scrawled Note (Sewers, coin)
• Stained Journal Fragment
• Torn Journal Fragment
• What Abides Below
• Urban Exploration - The Undercity!

Gallery

• 
  Entrance area to the sewers
  (by Martijn Petersen)
• 
  Eastern tunnel with fumes
  (by Martijn Petersen)
• 
  Pier for the sewage raft
  (by Martijn Petersen)

External links

•  Baldur's Gate/Sewers on the Forgotten Realms Wiki