The "valley of boulders" is located in Harriman State Park off of route 17 in southern orange county. This area is off the beaten path and so is rarely visited by anyone, let alone boulderers/climbers. There are some interesting rock formations, including cracks, caves and some rediculous overhangs.
Take rte 32 past the woodbury commons (or get off the NYS thruway at exit 16) and head south. 32 will become rte 17, and you stay on that for about 12 minutes till you see the Red Apple Rest in Tuxedo. If you park in the northeastern corner of that parkinglot you will find the trailhead of the Nurian Trail. Follow that trail for about 45 minutes till it crosses Stahahe Brook just below the North end dam of Lake Stahahe. From here you are about 15 minutes away. Stay to the left as you head back into the trees, and follow the white blazes up along side a seasonal stream, to the second tier of the waterfall. Cross just above that and continue across. Stay straight from there and you will go over a little rise and directly below you will be the boulders. Its a little tricky to get to because its off the path, but once you get there its definitely worth it! ENJOY