An erratic is a geological phenomena where a rock has been carried from afar to somewhere of a different rock type.

In this case the glaciers of the last ice age are thought to have deposited this boulder of hard, volcanic rock from the English Lake District on the softer limestone of the Yorkshire Dales.

Over the last 10,000 years, the boulder has prevented the erosion of the underlying soft rock, directly underneath leaving it perched. A winter's clear blue day (pretty rare in these regions) sets it off.

C+C welcome.

Ch