Popolopen Torne

Amazing place to hike.
1) The actual trail starts at the Fort Montgomery State Historic Site. But make sure to use the parking lot (aka. the additional parking lot) they have stones throw from the fort. Because the fort closes its parking lot at 5pm, however, the additional parking lot is ²⁴⁄₇. (Just ask them if you are confused of what I mean. Ask them: «do you have parking area which is extra and does not close at 5pm.» They should understand.)
2) Take the blue trail, which takes you all the way up to the top of the mountain.
3) The blue trail also bring you down the mountain.
4) Once you see the red trail, take it to finish the rest of the course.
5) It will take you across the bridge to reach the parking lot.
Also,
1) There is a monument on the top.
2) Fort Montgomery State Historic Site is a good Museum.
3) From Fort Montgomery State Historic Site you can also go to the Zoo and Bear Mountain Bridge.