Hidden basement

History
The Hidden Basement is something that was initially talked about by one of the game's developers when he talked to another player during the Gaming With the Developers event. The developer hinted that there was a "hidden basement in New Haven" and was "inaccessible after a certain point". The majority of the details about the basement, including how to enter it, was known after a user named tschaar14 posted and asked about it on the Borderlands official community forum, which in turn lead to a discussion that lead to the secret being revealed when a user accidentally stumbled upon the entrance.

Getting There
Entering the hidden basement is only possible during the Another Piece Of The Puzzle mission, where the Rakk Hive is killed. The blue hut can be entered only while the mission is active and will be rendered inaccessible once the Rakk Hive has been slain.

The basement usually has 3-5 Bandits, which can be Psychos, Mutant Midget Psychos, or Bruisers, and even a Badass in it. Objects contained in the basement include a silver and a red weapons chest, and some lockers. One bandit will be standing in front of the elevator (the side where it has no railings), while the rest will emerge from a hidden door in the corner of the room (to the player's right and back if he is on the elevator and facing where the first bandit stands).

Inside the basement there is a vaguely tree-shaped pile of greenish junk decorated with grenades. There is also a macabre version of the leg lamp from the classic movie "A Christmas Story," complete with it's own personal shield. Surrounding the 'Christmas tree' are a number of presents, including several chests and two weapon crates, one of which is guaranteed to contain a Gearbox manufactured weapon called the Rider. The red Flavor Text in the Stat Box for this weapon warns, "Careful...you might put someone's eye out." This is another reference to "A Christmas Story," in which Ralphie, the main character, asks for a Red Ryder BB gun for Christmas, only to be told by all the adults he mentions it to that, "You'll shoot your eye out!"

The official forum where discussion of the basement first started

Trivia

 * The music track heard during the Rakk Hive battle will be playing in the Hidden Basement.