Bothwell Castle is a large medieval castle, sited on a high, steep bank, above a bend in the River Clyde. Construction of the castle was begun in the 13th century by the ancestors of Clan Murray, to guard a strategic crossing point of the Clyde. Bothwell played a key role in Scotland's Wars of Independence, changing hands several times.
The huge cylindrical donjon was built in the 13th century, but before the rest of the castle was completed it was severely damaged in a series of sieges. Rebuilding in the early 15th century enlarged the castle, but it was abandoned by the 18th century. The present ruin is rectangular, with the remains of the donjon to the west, and the later Great Hall to the east. The courtyard is enclosed by long curtain walls, with round towers at the south-east and south-west corners.
References:Château de Niort is a medieval castle in the French town of Niort. It consists of two square towers, linked by a 15th-century building and dominates the Sèvre Niortaise valley.
The two donjons are the only remaining part of the castle. The castle was started by Henry II Plantagenet in the 12th century and completed by Richard the Lionheart. It was defended by a rectangular curtain wall and was damaged during the Wars of Religion. In the 18th century, the castle served as a prison.
The present keeps were the central point of a massive fortress. The southern keep is 28m tall, reinforced with turrets. The northern tower is slightly shorter at 23m. Both are flanked with circular turrets at the corners as well as semicircular buttresses. Each of the towers has a spiral staircase serving the upper floors. The Romanesque architecture is of a high quality with the dressed stones closely jointed.