Erratic geology...

This glacial boulder is a well-known meeting point on Cannock Chase. It even has a car-park named after it. Many walks on the Chase start here - including the AA recommended one.

It's also called the 'erratic' boulder, not because of its odd, semi-phallic shape, but because, in geology, an erratic is a stone that is quite different from those around it.
In this instance, this boulder is a stranger to those around it because it was swept down from a place hundreds of miles away to the north during the glacier movements of the Ice Age.