It’s a good old D&D dungeon crawl called “The Vault of Zerduzan“.

You can download it here in PDF format: link

Edit(04/19/10): Huzzah! “The Vault of Zerduzan” won for Best Evil Cultist Hangout. I’m flattered and humbled especially to be published along side the other winners all of whom did excellent work.

I’d like to give a big thanks to all the judges! Here’s a link to the compiled winners in one spiffy PDF file:
2010 One Page Dungeon Contest Winners