At the south-west end of the island, looking across Loch Breachacha to the open Atlantic, stand the two Breachacha Castles. The old castle is a small, much-restored tower-house with a curtain wall; the new castle nearby is an 18th-century Georgian residence with later 19th-century extensions.
The old castle has been privately restored and was for years used as a base for a Scottish charity that ran adventure courses on the island. Neither building is generally open to visitors, but you can walk right up to the walls. The setting — open machair grassland, white shell beach, the islands of Mull and the Treshnish in the distance — is what most people come for.