Rothesay Castle

Rothesay Castle is unique in the British Isles for its circular curtain wall. Most medieval castles are rectangular or shaped to their site, but this one was built as a near-perfect circle. That plan, with its round towers and water-filled moat, makes it one of Scotland's most distinctive castles, and its early 13th-century stonework makes it one of the oldest surviving stone castles in the country.

The Duke of Rothesay is the Scottish title held automatically by the heir apparent to the British throne, the equivalent of the Prince of Wales in England. It has been conferred since 1398, when it was first granted to David Stewart, the eldest son of Robert III. King Charles III held it as heir, and it now belongs to Prince William, giving the castle a lasting royal link.

Rothesay Castle is looked after by Historic Environment Scotland, with a small admission fee of around £6 for adults; HES members go free. It stands right in the centre of Rothesay, a few minutes' walk from the ferry pier, which makes it an easy start or finish to a day on Bute.

Norwegian Vikings attacked Rothesay Castle in 1230, reportedly hacking through the walls with axes rather than climbing them; the damage is still visible in the stonework today. The Scots retook it soon after. It was besieged again by the English during the Wars of Independence and changed hands several times before becoming a favoured home of the early Stewart kings.