Dun Ara was a stronghold of the MacKinnon clan who held the land here from 1354 onwards. The castle was still in use until the 17th century when it was abandoned. The castle was probably built on the site of a previous Dun or fort. The castle had a surrounding wall protecting a central keep or building on the main outcrop of rock. The location was valuable as it protected a harbour of boat landing as well.
The castle was fortified by enclosing the entire rock summit with a curtain-wall of stone and lime, which varies from about 1.3 m to 1.8 m in thickness. It is best preserved on the north-east side, where it rises to a maximum height of 1.8 m, but little remains on the south-west and south-east sides. The masonry was built with coarse, lime mortar, much of it has washed out of the facework giving it the appearance of dry-stone walling. It is possible that in places the lower courses of masonry pre-date the medieval castle and belong to an earlier fort that occupied the same site. The entrance is on the south-east side.
References: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.