Located on the edge of Fort Greene and Downtown Brooklyn lies a 30-acre park that dates back to the Revolutionary War. Fort Greene Park is Brooklyn’s oldest park and it has centuries of history to its name. Here are ten things you might not know about the historical park.

10. There’s a Secret Elevator in the Prison Ship Martyrs’ Monument at Fort Greene Park

The Prison Ship Martyrs Monument, located in the central Doric column at Fort Greene Park, used to contain a double-helix stairwell when it was first constructed. It originally led to an observation deck on top when the monument first opened. The staircase was eventually replaced by an elevator, but this was also later removed after falling into disrepair.

Now, there is only a single iron ladder, with regularly spaced landings, which leads to the top. Today, the interior and observation deck of the Prison Ship Martyrs Monument are normally closed to the public.