Local cave at St Medans (back bay) in Galloway. The colours are not enhanced, but best seen at sunset and when the cave is still wet from a receding tide. Don't know if it has a proper name, though we do have our own name for it, and I'll leave that to your own imagination!

EDIT: The colours at the bottom of the cave are various algae, many of the other colours (reds, blues, purples and goldish green are most likely deposits of copper sulphides and oxides. Copper was mined near here in the middle-ages...