One of my favorites that is not so big but so cool is the old belt line train station at Starin and Amherst. It's sunk below the street next to the tracks and has this old cobblestone driveway down to it. You can rent it on airbnb for $300 a night.

We had a pretty shitty experience at the park (ask (e:paul)) but Hoyt lake was especially bad that day. I assume it was the rain.

LOL, the caption totally does not match!
Wow @ that last picture. Beautiful!