At first I thought these were guard stones, but then I realized their placement is not very typical for guard stones, which were placed at the corners of entranceways to protect the corners of the buildings from the wheels of carriages. Later I was told they are actually old cannon , but their purpose is still not clear. According to Wikipedia, in the 17th and 18th centuries “old cannon were often used as bollards on quaysides: they would be buried in the ground muzzle-first to approximately half or two-thirds of their length, leaving the breech (rear end) projecting above the ground for the attachment of ropes. ” These obviously are not located on a quayside, but reading this made me come back to another idea I had: that the cannons with the knobs were used as hitching posts. (Of course boat ropes and horse reins differ greatly, but whereas the boat ropes would have been tied around the whole cannon, my guess is that the horse reins could have been tied to the small knob on ...