Balancing Rock Trail

How is it balanced there? 20 tonnes or more of volcanic rock balanced precariously on a ledge above the waves of St. Mary’s Bay.
The 1.7 km Balancing Rock Trail leads visitors from the parking lot, just off Highway 217 outside Tiverton, through woods and bog to the southern shore of Long Island.
At the end of the trail, a series of 235 wooden steps provide access to a cliffside viewing platform overlooking the 20-foot high finger of basalt.

---