This content has been retired and is no longer available in game.
These adventures formerly appeared in The Daily Dungeon before the revamp on August 17, 2013. The Dungeon comprised ten rooms, each containing a monster (see the main page for details), stat test, elemental test or reward. The rooms were the same for all players on any given day.
Likely not an adventure location. Probably worked like Fernswarthy's Basement, with its own php script.
History
There apparently used to be an adventure in the Daily Dungeon which dropped the gasmask - it is uncertain whether it was a monster drop, a non-combat or a possible reward in one of the chests: but Jick deleted it, apparently by accident, in mid-2004, and the text of that adventure is now lost to history.