At the southern end of Bute, in a sheltered hollow reached on foot from the end of a farm lane near Kilchattan, stand the ruins of St Blane's Church. Most of what survives is Norman work, but a monastery stood here in the 6th and 7th centuries and fragments of its enclosure remain around the church.
It's one of the most atmospheric spots on the island, especially in evening light. Half a mile west, Dunagoil is an Iron Age fort whose stones were once burned so fiercely that they fused into glass.