Celtic Quest Coasteering

Coasteering — scrambling, swimming and leaping along the base of sea cliffs — was invented on this coast, and Celtic Quest is its single-minded specialist: coasteering is all they do, every day of the season, on the volcanic coastline around Abereiddy and the Blue Lagoon. That focus shows in the guiding: routes read to the day's sea, jumps always optional, ages from primary-school upwards catered for.

Wetsuits, buoyancy aids and helmets are provided; you bring trainers you don't mind drowning and a change of clothes. Sessions run to the tide rather than the clock — times and booking on their site, and book ahead in school holidays.

The Blue Lagoon itself — the flooded slate quarry the cliff-divers use — is the famous finale when conditions allow. For the wider picture of who does what on this coast, see coasteering in St Davids and the wild swimming guide for the unguided version of getting wet.