Just to the north of Culmstock, at Culmstock Beacon, is one of a chain of Elizabethan beacons built to warn of possible invasion by the Spanish Armada. On 5 November 1380, King Richard II granted Sir William and Lady Margaret Asthorpe a licence to crenellate the Hemyock manor house, meaning the permission to fortify it. Over the centuries, Hemyock Castle had many notable owners including Lord Chief Justice Sir John Popham. During the English Civil War it was held for Parliament, subjected to a brief but brutal siege and eventually "slighted "to destroy its military value. Parts of the castle walls, towers and moat still remain. They are a scheduled ancient monument and include displays of history and archaeology. The castle was also owned by General Sir John Graves Simcoe the first lieutenant-governor of Upper Canada in 1792. He is buried at Wolford Chapel near Dunkeswell. The chapel is now owned by the Province of Ontario.