The large St Regulus Church (1127-1144) was perhaps built to house the relics of St Andrew. Today, from the top of the tower with its 151 steps, you can admire the panoramic view of St Andrews. In 1150, the church was replaced by the largest cathedral ever built in Scotland. After the Reform, this building, despite its prestige, served as a stone quarry. All that is left is the 12C chevet, the west gable from the late 13C and the southern nave wall.