Trwyn Du light

at the top end of the Menai Strait, just off Anglesey. A delightful, deep bell sounded every 30 seconds, in the murky visibility. The wording on the lighthouse mentions, perhaps fussily, that there is no passage landward. It was designed by one James Walker, who "also pioneered, unsuccessfully, the use of a primitive water closet, comprising a specially designed drain exiting at the base of the tower. The stepped design of the lighthouse may have helped water exit the closet, but surges of seawater made its use difficult during heavy weather."