What happened at Amroth is one of the clearest records anywhere of the moment when Britain became an island. As the last Ice Age glaciers retreated, meltwater raised global sea levels, and the broad plain that connected Wales to the rest of Europe was slowly swallowed. The trees did not have time to migrate inland. They drowned where they stood. Their roots are now permineralised, their wood blackened by millennia underwater, and they appear at the bottom of the beach only when the tide pulls far enough back. Antlers and bones tell of red deer and aurochs that grazed here. The flints tell of people - hunters who walked this same shoreline when it was still inland forest, who knapped tools while watching the sea inch closer every generation. They did not know what was happening, exactly, but they knew enough to leave.

Amroth is the start. The Pembrokeshire Coast Path - one of Britain's great long-distance walking routes - launches from this beach and runs west for 186 miles around the Welsh coast to St Dogmaels. Since 2012, the path has also formed part of the longer Wales Coast Path, which continues east from Amroth over Telpyn Point toward Pendine. The Knights' Way begins here too, heading north to St Davids Cathedral, and the Cistercian Way passes through. Whatever distance you intend to walk, the first step is the same: the long sand of Amroth, with the village strung along the curve of Carmarthen Bay, and the headland rising at either end. The beach has earned the Blue Flag standard for cleanliness, most recently in 2020. The eastern end has a seasonal lifeguard. The car park is run by the Pembrokeshire Coast National Park Authority, into which the entire village falls.

Until the end of the 19th century, this was anthracite country. Pembrokeshire's coal seams - rich, hard-burning, geologically isolated from the larger South Wales coalfield - ran along this coast and inland. Amroth was an important mining parish. Today the only traces are slight: tramway beds in the bracken, the suggestion of an old shaft, the names of vanished pits. The bigger story is east of here, at Landshipping, where in 1844 the sea broke into a colliery seam beneath the river and killed forty miners. The Amroth pits were smaller, and they closed quietly as the industry consolidated elsewhere. The beach was busier than the mines now. By the early 20th century, Amroth had begun reinventing itself as a seaside village, which is what it has remained ever since.

A mile inland from the beach, the parish church of St Elidyr stands among yew trees. It is Grade II* listed, with parts dating back centuries, named for a Welsh saint about whom little is reliably known - the name surfaces in early Welsh hagiography, but the historical figure is faint. The castle a short walk east is no more reliable. The present Amroth Castle is an 18th-century house dressed as a medieval fortress, owned for two decades by Owen Colby Philipps, the shipping magnate who later bought the White Star Line. The parish, recorded as Amrath on a 1578 map of Pembrokeshire, takes its name from Welsh, probably meaning 'on the brook called Rhath.' It is the kind of place where the old names persist, sometimes longer than the things they once described.