I happened across this article in Nature: 'Constraints on global mean sea level during Pliocene warmth'.  It shows a nice vertical profile in part of the Coves d'Arta, Mallorca and a picture of a deep part labelled 'Infern' (Hell ?) and some speleothems which are interpreted in the article as...

A question about Boscastle Blowhole (S entrance at SX 09370 91537 :  I have looked at some Youtube videos of the 'Blowhole'.  eg https://www.youtube.com/watch?v=v22NZ90tMjY    This appears to mostly  operate as the blow- back type in which an incoming swell seals the rather low entrance and...