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.
The stone church of Gamla Uppsala, built over the pagan temple, dates from the early 12th century. Due to fire and renovations, the present church is only a remnant of the original cathedral.
Before the arrival of Christianity in Sweden, Gamla Uppsala was the seat of Swedish kings and a ceremonial site known all over northern Europe. The settlement was home to royal palaces, a royal burial ground, and a great pagan temple. The Uppsala temple, which was described in detail by Adam of Bremen in the 1070s, housed wooden statues of the Norse gods Odin, Thor and Freyr. A golden chain hung across its gables and the inside was richly decorated with gold. The temple had priests, who sacrificed to the gods according to the needs of the people.
The first Christian cathedral was probably built in the 11th century, but finished in the 12th century. The stone building may have been preceded by a wooden church and probably by the large pagan temple.