Shaffer Rocks is a great little crag in south central PA, featuring some great TR routes and bouldering, and a few trad lines. The rock is a good quality Weverton quartzite that seems to dry pretty quickly, despite being a north facing wall.
Because the crag is on the Appalachian Trail, there happens to be a very nice (fully stocked) cabin less than 100 yards from the base. This can provide for a relaxing weekend of climbing, cooking, beer drinking. The cabin is named The Hermitage and can be rented for $25/night Sun-Wed or $40/night Thu-Sat. These rentals can fill months in advance. More information can be found on the Potomac Appalachian Trail Club's Website.
Getting There
Coming from the east or west on 30, one will want to find 233 running through Caledonia State Park and intersecting 30 there. Take 233 south to South Mountain Restoration Center. Go through SMRC until Old Forge Road is on your right. Take this several miles to after the AT crossses the road you will see Swift Run Road on your right (dirt). Take this up hill for a short period till there is a large pull off on a sharp left turn. Follow the blue blazes for 20 to 30 yards and break left to the ledge of the main face. If one continues on the blue blazes you will skirt the rocks around the right side and come to the Hermitage cabin. Up from the cabin to your left is the corner of the main face.
Photos of Shaffer Rocks (aka The Hermitage) Slideshow