The Lost Bastille can be accessed from the Forest of the Fallen Giants via the bird's nest past The Pursuer's boss chamber, or via the pirate ship accessible in No-Man's Wharf. Note that a gate prevents access to a portion of the Lost Bastille if you arrive here from the Forest of the Fallen Giants. There are two ways to get to the other side of the gate without going through No-Man's Wharf. The first being by obtaining the Antiquated Key and opening the door left of the well with a cage containing three hollows (This may have to be done from the back side). The second way is by falling off the wall through the hidden door in the room right past the set of two gates while wearing the Silvercat Ring and having around 1100 HP. This is similar to the Forest of the Fallen Giants entrance. There is no way to return to that bonfire unless the player has sat down and rested at it.
The Lost Bastille eventually leads to Sinner's Rise, terminating with the boss fight there.
- The Tower Apart: After arriving from the Forest of Fallen Giants, the bonfire will be in the room you are dropped in.
- McDuff's Workshop: From the first bonfire, leave the room and navigate the rubble to an adjacent battlement. Avoid a lone Jailer and pass through the tower housing Lucatiel of Mirrah. Exit from the other door and travel straight down the battlement, past several Stray Dogs, and two Undead Jailers. Eventually, you will come upon a barrel at the top of a large staircase. Push the barrel, and, if it hits the wall at the bottom, it will destroy the wall, revealing the bonfire.
- Servants' Quarters: After defeating the Ruin Sentinels, climb the stairs in a corner of the room. At the landing, there will be a corridor with very small cells, leading to a room with various furniture. The bonfire is in the far left, from the entrance.
- Straid's Cell: After acquiring a Fragrant Branch of Yore, travel to the tower across from Sinner's Rise and ascend to the room with a large group of Mummified Undead. Unpetrify Straid of Olaphis to access the bonfire behind him.
- Exile Holding Cells: From the Servant's Quarters bonfire, exit the room, with the door on the opposite side of the bonfire. After crossing the planks, turn right and, after entering the tower, left. Travel to the end of the battlements and drop off of the roof. From the courtyard you landed in, enter the locked door by using the Antiquated Key (which may be found earlier in the level in the room of enemies closest to the Tower Apart Bonfire). Cross the room and break the planks patching the hole in the wall. After entering the next courtyard enter the doorway on the left and climb the ladder. At the top, head right, until you come across a room that can be entered.
Alternatively, it is the first bonfire encountered when entering the Lost Bastille from No Man's Wharf.
- The Lost Bastille is named after The Bastille, a famous prison in France that was sieged by revolutionaries during the French Revolution.
- If one listens closely near the Exile Holding Cells bonfire area, you will hear low moaning and whispers.
- Upon entering the Exile Holding Cells bonfire area from No-Man's Wharf, there is an undead in one of the first cells that is leaning on the cell door. It can be attacked through the door and blood will even come out, but it cannot be killed, nor does a health bar appear.
- While at Heide's Tower of Flame, If one looks to the entrance to No-Man's Wharf, they will be able to see part of the Lost Bastille. The part seems to inaccessible.