The Black Diamond Mines Preserve is a 6,000 acre area of beautiful, rolling, grassy hills. Peppered among these hills are the remains of 12 coal mines, and several old mining towns. With about 40 minutes of walking, you'll find yourself at the entrance of a prospect tunnel. You can walk about 200 feet into the tunnel, (provided you brought a flashlight) before you run into a locked iron gate. The hike would be a nice easy walk, but Thursday is leg day at the gym, and Friday is hike day. I pushed through my protesting quads, and had a wonderful time messing around in an abandoned tunnel.