In 1823 hundreds of Welsh miners hacked, by hand, the four tunnels here out of solid rock. It was a remarkable feat. The tunnels lead to a strip of beach where you can plunge into the sea from Victorian tidal bathing pools.

Extensive exhibits include sepia photos depicting the site in the 19th century, conveying a world of woollen bathing suits, segregated swimming and boating etiquette ('Gentlemen who cannot swim should never take ladies upon the water').