Anglesey the island. The highest six are Holyhead Mountain, ; Mynydd Bodafon, ; Mynydd Llaneilian, ; Mynydd y Garn, ; Bwrdd Arthur, ; and Mynydd Llwydiarth, . To the south and south-east the island is separated from the Welsh mainland by the Menai Strait, which at its narrowest point is about wide. In all other directions the island is surrounded by the Irish Sea. It is the 51st largest island in Europe, and just five square kilometres smaller than Singapore. There are several small towns scattered around the island, making it quite evenly populated. The largest are Holyhead, Llangefni, Benllech, Menai
Salt Island, Anglesey a whole is strictly monitored and is virtually impossible for pedestrians to enter. Salt Island, Anglesey Salt Island () is joined to Holy Island, Anglesey, in North Wales. It is a natural provider of shelter for the town's Old Harbour from the Irish Sea and is part of the Port of Holyhead. The island gained its name by a factory located on it which processed sea water in order to extract sea salt. By the early 18th century, the sea salt was often mixed with rock salt (often smuggled onto the island) to increase the quality of the factory's product.