Earlier this year the Park Slope Armory reopened after a massive renovation, now housing a track, a basketball court, and much more. Of course, when it was built in 1895, it housed the 14th Regiment of the National Guard. The sporting events began in 1939, when an indoor professional baseball league was formed to play an indoor season there, and it was around that time the Armory's purpose changed.

Military units were eventually all moved out to be closer to the new transportation corridors created post-WWII, which were not in Park Slope. Check out Thirteen.org's look at the past, present and future of the Armory in their latest City Concealed video: