The Star Castle is in the shape of an eight-pointed star and features on the flag of the Council of the Isles of Scilly. It is at the centre of a fortification system around the west side of St Mary’s known as the Garrison. The walls of the castle take the shape of an eight-pointed star. It comprises an outer wall around the outcrop of Hew Hill, protecting the town and the castle, with strategically placed gun batteries at regular intervals around the outer wall, allowing covering fire at all angles.