One of the most dramatic sights on this extraordinary stretch of coast is this 13th-century hermit's chapel, wedged into a slot in the cliffs, just out of reach of the sea. Steps hacked into the rock lead down through the empty shell of the structure and on to the rocks below, where there's a particularly picturesque rock arch, perpetually pounded by the waves.
The chapel is named for a 6th-century Irish preacher who, according to legend, was being pursued by pirates when the cliff conveniently opened and enfolded him, protecting him from his attackers. In gratitude, he built the original chapel and lived here until his death in 586.
St Govan's is well signposted from Bosherston and there's a car park at the top of the cliffs. The road to St Govan's passes through MOD land and is closed at certain times (call ahead to check it is open).