Orivirran saarto is a ruin of the 16th century fortress. It was built probably in 1540's, because in 1546 Russians complained about Swedish cutting forest and gathering stones in Orivirta. There were probably a main castle, outer fortication, watchtower and dock. During 16th century it was garrisoned by 400-600 men and 5-10 cannons.
In 1592 Russian cossacks destroyed the fortress. In a fight over 200 men were died and Swedish lost a ship and several cannons. After defeat Orivirran saarto was changed to guard place and fortified again during the Russo-Swedish War in 1656–1658.
Nowadays there remains some ruins of the fort restored by the Finnish National Board of Antiquities. There's also a memorial erected in 1965.
Dating from the 15th century, Kisimul is the only significant surviving medieval castle in the Outer Hebrides. It was the residence of the chief of the Macneils of Barra, who claimed descent from the legendary Niall of the Nine Hostages. Tradition tells of the Macneils settling in Barra in the 11th century, but it was only in 1427 that Gilleonan Macneil comes on record as the first lord. He probably built the castle that dominates the rocky islet, and in its shadow a crew house for his personal galley and crew. The sea coursed through Macneil veins, and a descendant, Ruari ‘the Turbulent’, was arrested for piracy of an English ship during King James VI’s reign in the later 16th century.
Heavy debts eventually forced the Macneil chiefs to sell Barra in 1838. However, a descendant, Robert Lister Macneil, the 45th Chief, repurchased the estate in 1937, and set about restoring his ancestral seat. It passed into Historic Scotland’s care in 2000.
The castle dates essentially from the 15th century. It takes the form of a three-storey tower house. This formed the residence of the clan chief. An associated curtain wall fringed the small rock on which the castle stood, and enclosed a small courtyard in which there are ancillary buildings. These comprised a feasting hall, a chapel, a tanist’s house and a watchman’s house. Most were restored in the 20th century, the tanist’s house serving as the family home of the Macneils. A well near the postern gate is fed with fresh water from an underground seam. Outside the curtain wall, beside the original landing-place, are the foundations of the crew house, where the sailors manning their chief’s galley had their quarters.