Tenby (Welsh language: Dinbych-y-Pysgod, "little town of the fishes or little fortress of the fish") is a walled seaside town in Pembrokeshire, south-west Wales, lying on Carmarthen Bay, and is a popular seaside holiday resort. Attractions in Tenby include four kilometres of sandy beaches, the 13th century medieval town walls including the Five Arches barbican gate, 15th-century St. Mary's Church, the Tudor Merchant's House (National Trust), a museum with art gallery, and the Pembrokeshire Coast Path, part of Britain's only coastal National Park. Boats sail from Tenby's harbour to the monastic Caldey Island while St Catherine's Island just offshore is linked to the town at low tide. The town is served by Tenby railway station.