Tenby (Welsh: Dinbych-y-pysgod, meaning little town of the fishes or little fortress of the fish) is a walled seaside town in Pembrokeshire, south Wales, on the western side of Carmarthen Bay.Notable features of Tenby include 2.5 miles (4.0 km) of sandy beaches; the 13th century medieval town walls, including the Five Arches barbican gatehouse; the 15th century St.