hvered wrote:There are three tidal pools all at Margate and quite close, though one is now disused. They are opposite Nayland Rock, Fulsam Rock and Walpole Rocks, it may be they were formerly sites for a lighthouse or beacon.
The chalk hill of Cliftonwille at Margate has a cave complex, the shell grotto too may have been connected with a mining operation. The tidal pools could be accidental features, pits originally part of the mining operation that filled up with water after sea levels rose.
This seems to be true for Gotland which has several lakes. I have no idea what Gotland was producing/trading/manufacturing but it was important to a lot of people (pirates, Teutonic Knights, Hanseatic League) at various times. Faro island, separated from Gotland by a narrow strait, is known for its rauks or sea-stacs.