2. There Used To Be A Tunnel From the Armory Into Prospect Park
The Park Slope Armory was built with a tunnel that led from the 14th Street side of the building into the middle of Prospect Park. The bricked-up entranceway in the above basement storage room is the former entrance to the tunnel. You can feel a breeze from the removed bricks on top of the entranceway. But it is believed that large portions of the the tunnel collapsed due to the construction of the subway and from residential expansion in Park Slope.