Cornwall was once inhabited by a number of large and fierce giants but the largest and fiercest of them all was the giant known as Wrath or Ralph of Portreath.
Wrath lived in a large cave along the cliffs at Portreath where he would lie in wait for passing ships, then wade out to sea, attach the ships to his belt and and drag them back to his lair which became known as Ralph's Cupboard. There he would dine on the sailors, choosing only the fat ones and throwing away the thin ones. Even sailing past at a safe distance wasn't enough to protect the unwary from Wrath's attentions as he would stand atop the cliff and throw huge boulders at them until they sank.
(And when the tide is low you can still see the rocks that Wrath threw scattered across the seabed.)
Fishermen from St Ives avoided the area at all costs saying that no one who strayed into Ralph's Cupboard ever returned alive. Wrath is said to have died when the roof his cupboard fell down upon his head, leaving his former lair as an an open gorge into which the sea flows at high tide.