Trematon Castle was the caput of the feudal barony of Trematon. It overlooks Plymouth Sound and was built probably by Robert, Count of Mortain on the ruins of an earlier Roman fort: it is a motte-and-bailey castle and dates from soon after the Norman conquest.
Trematon Castle, like Restormel Castle, has a stone shell keep raised on an earlier motte. Although in ruins, much of the Norman walls remain standing, so that the original form of the Castle and keep are clear. The internal diameter is approximately 21 metres. A rectangular gatehouse, built in 1270, has two floors and a portcullis. Both are in good condition. The castle is currently open to the public.
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.