City gates

City Gates is a secret map which is only accessible through the metro station at Turnip Hill that leads to Open Sewer. The gates are the entrance to the underground city, which is a popular myth in Stalburg and is probably the hideout for Stalburg Underground.

Gameplay
It starts in a collapsed tunnel with a minitrain. Mark is in the Open Sewer metro station, and finds a door that leads to an elevator that takes him down to a large cavern with a set of heavy blast doors and code panel. Entering the incorrect code will give the player the "Underground Justice" achievement, in which Mark is incapacitated and captured. What follows is a surreal sequence, Mark is interrogated by a person in a diving suit and "sentenced" to death for the crimes he's committed, and executed. The execution device he is fed into is likely The Machine. The blast door controls can be unlocked with the code "4027", but this will cause the game to fake a BSOD and boot back to the main menu.

Interrogation Transcript
[Person 1] "This is an interrogation. Number: 1396."

[Person 2] ''Name: Markku Mark Siltanen. Age: Thirty-six. Social security number 672-834-027X.''"

[Person 1] Charges?

[Person 2] "Forgery, trespassing, bribery, burglary, and, negligence."

[Person 1] "Interrogation."

[Person 2] "You've ignored an important task that could have saved this city and have performed several other deeds that are against the law. Why?"

[Person 2] "His condition is too bad. He can't answer the interrogation questions. Let's move in to the final step."

[Person 1] "Sentence?"

[Person 2] "Because of his condition, he is unfit for any manual labor. The sentence is going to be... death."

Gallery
=Trivia=


 * A map in the S.N.W control room has pictures of the city gates and interrogation room, and marked the site as "NW". This insinuate the doors don't guard a "city" at all, and is a nuclear waste disposal site.
 * Elo's drawings in her hideout under the Castle Rock Drawbridge accurately depict the elevator, cavern and blast doors, as well as a drawing of herself happily entering the city with a entity resembling Mörkö.
 * When noclipping into the room which houses The Machine, a covered corpse can be seen.