It is a beautiful building http://en.wikipedia.org/wiki/Monadnock_Building in a city with many beautiful buildings. Some say that the coffee shop http://www.intelligentsiacoffee.com/locations/view/Monadnock... is the best in chicago, and i hear that the NY staff likes it as well.
There are some particular mysteries of the building that Matasano is privy to. For example the "John Malkovich" door with its own office number: http://img228.imageshack.us/i/img0226yl.jpg/. And there is the fact that we are the only office on the 18th floor of a 16 story building. (And despite First Blood trying to get me with the swimming pool, that is not part of the deal.)
And the people here are absolutely awesome.