Two limestone caves in the hillside at Tremeirchion, Ffynnon Beuno and Cae Gwyn, where Victorian excavations turned up Palaeolithic flint tools and the bones of Ice Age animals — among the earliest traces of humans in Wales. They sit on private land, so it’s a look from the public footpaths rather than a scramble inside. Prestatyn station is about 9km to the north.
