We've all become intimately familiar with Gotham's home for the criminally insane thanks to the Arkham series of video games, but we don't have anything on Lego builder Thorsten Bonsch, who spent a year building the asylum with Lego bricks.
You can check out a full gallery of photos of the impressive structure on Bonsch's Flickr gallery. For a deeper look at the creation, however, Bonsch documented the whole endeavor and put it all in a book, which you download and check out for free here.
There are small details all over the piece, including both villain and hero cameos like Batman (obviously) and Poison Ivy and Clayface. There's a lot more to the whole piece than would appear at a first quick glance, and it's all very impressive.
[Source: The Brothers Brick]