Between [Mullion] and the Lizard is a fine headland, the Rill, and on its summit are a number of loose, rough stones, known as the Apron String, which the country people say were brought here by an evil spirit, who intended to build with them a bridge across to France for the convenience of smugglers. He was hastening along with his load, which he carried in his apron, when one of its strings broke, and in despair he gave up the idea.
From ‘Cornish Folk-Lore’ by M A Courtney, in the Folk-Lore Journal, v5 n1 (1887).