Bass Rock Castle was originally the 8th century refuge of St Baldred and a mid 16th century chapel of Saint Baldred still remains. In the early 13th century, Robert Lauder founded a fortification on the gentler south-west corner, of this inhospitable rock in the Firth of Forth. In the 16th century, Lauder of the Bass founded the stone artillery courtyard fortress and when purchased by the Crown in 1671, it became a State prison mainly for the Covenanters. In 1691 four imprisoned Jacobite officers captured the fortress for the exiled King James VII and held it for nearly three years. Dismantled in 1701, it was repaired in 1902, when a lighthouse was built on the site of the governor's house. The southern slope has the only place to land and a long curtain wall occupies the terrace above, isolating the landing from the remainder of the rock. Projecting at right angles from the curtain wall, is a battlemented wall with an internal stair which ends with a round battery. Wide gun-ports in the battery and the wall, cover the approach to a gatehouse. A mile south is Tantallon Castle.