The late antiquity and medieval Palmatis fortress is placed at the east end of Onogur village. The Roman road between Durostorum and Marcianopolis used to pass nearby. The fortress is situated on a high plateau, lowering down to the northeast towards the dry valley. The Early-Christian basilica from the time of Emperor Justian the Great has been revealed in Palmatis fortress.
Caernarfon Castle in Gwynedd, Wales, is recognised around the world as one of the greatest buildings of the Middle Ages. It was a motte-and-bailey castle from the late 11th century until 1283 when King Edward I of England began to replace it with the current stone structure. The Edwardian town and castle acted as the administrative centre of north Wales, and as a result the defences were built on a grand scale. There was a deliberate link with Caernarfon's Roman past, and the Roman fort of Segontium is nearby.
While the castle was under construction, town walls were built around Caernarfon. The work cost between £20,000 and £25,000 from the start until the work ended in 1330. Although the castle appears mostly complete from the outside, the interior buildings no longer survive and many of the building plans were never finished. The town and castle were sacked in 1294 when Madog ap Llywelyn led a rebellion against the English. Caernarfon was recaptured the following year.