Protrusion, Explosion

The Scotsman has a full account of this mine that has just been dealt with by a Royal Navy bomb disposal unit in a controlled explosion on the island of Eigg. It was thought to have been a buoy and was used by children and animals as a plaything, until recent storms and sand movements revealed something sinister. The composition of Eigg itself, with its protruding volcanic core, makes the wartime mine appear to be a microcosm of the island's geological past.

Scottish Islands Explorer - elements can spark interest years later