Here are the rocks (I've found so far) in Washington Heights, some of them I've climbed on, some not. When I head out bouldering next time I will take pictures for topos. But for now here are the locations (with thanks to Google maps):
Edgecombe North (Edgecombe Ave between 162nd and 163rd)
Description: A 70 yard long mostly vertical "cliff" with the height ranging from 10-16 feet. There are blast-holes every 6-8 ft, occasional graffiti/painted over patches and the rock its self is clean, and the top out is perfect.
The cliff is divided into section by three bays containing benches and direct sidewalk access. Between the benches are fenced off grassy patches with a low to mid glass count, so bring a Pad. The fence is at least 2 yards from the cliff so low collision likelihood.
The number of lines to climb here is as far as your imagination can take you. And its not just for the 'rdcore, there is a ton of easier routes too (5.6, 5.7 etc).
Warmup Slab (5.5+?): On the far left, just round from the vertical face is a small 3 move slab, that can be as difficult as you want it to be.
Just left and behind Edgecombe North facing the playground is a small, 8 foot boulder surround by some grass. It really only contains an easy slab climb in the middle (using no obvious holds/cracks) called Spiderman (shouted at/to? me the day sequel 3 was released)
Edgecombe South (Edgecombe Ave between 160th and 162nd)
Description: The south cliffs are a little higher than their northern neighbor, maybe 15-20 feet in places. Again direct sidewalk access (in the central section) plus 2 yard of low glass :-) grass. The climbing is vertical and the top out is rounded, with mud and grass, ie. not so fun. Also it's a parks and recs "house and garden" so access once on top might be problematic. Again some paint and graffiti, but the climbing is excellent. At first glance the lines are not as obvious as those of the north cliffs. But a close up inspection, reveals numerous smallish crimps and smears.
Shoot the Moon (5.7): Start directly below a crescent and blasthole in the central section, climb to this crescent and then move left and up to finish.
Blast the Moon (5.6): Start as with shoot the moon and at the crescent move up and right into the bottom of the blast hole/undercling. From here go straight thru to the other end of the blast hole and up to finish.
Either side of the central section, described above, are "fenced off" areas, with high weeds/small trees. The fences are broken in places for access. I have not yet climbed here.
Edgecombe Backside (Edgecombe Ave between 162nd and 163rd)
Description: On the far side of the Playground Boulder is a sloping rock down to a small dirt path. Along this path on the right (or possibly the left) is a small section of rock 10 yards long and 10 feet high. Looks climbable but for the spray paint, high glass count and general sketchyness of being out of sight of the road/park.