Kilmartin Castle, a small tower house, dating from about 1580, stands above the village. Kilmartin was a property of the Campbells, many of whom are buried in the churchyard. John Carswell, Rector of Kilmartin and later titular Bishop of the Isles, lived here before moving to his new residence at Carnasserie Castle. The castle comprises an oblong, three-storey main block, with round towers to the north-east and south-west corners, as well as a small stair tower in the west front. Formerly ruined, it has been restored as a private house in recent years. Shot holes and iron yetts over the windows have been retained.
Carswell moved into Carnasserie Castle in 1565 and died in 1572, so kilmartin castle must have been built before either date.
The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.