This memorial, dedicated to the Union forces of the Civil War, is one of three triumphal arches in NYC — and we've already seen the other two. It was also partially filled with puppets until a couple of years ago, when a leaking roof forced them to find new quarters.

This column memorializes the Maryland 400, whose gallant efforts and sacrifice during the Battle of Long Island (the first major battle of the Revolutionary War) "saved the American army", according to a plaque on the monument, allowing the Americans, severely outnumbered and outgunned by the British, to successfully retreat to Manhattan. Have you ever looked at a Maryland quarter and wondered how the state got its nickname? Well, now you know!

Built in 1869, this building sits beside a well that once pumped about 750,000 gallons of water per day into a nearby reservoir, which in turn fed the park's artificial watercourse (all the bodies of water in Prospect Park are man-made). When Brooklyn became part of New York City in 1898, it gained access to the city's water supply system, and the well and reservoir were no longer needed.

I just learned you can recycle fishing line.

The Gale House

That's a new one to me!