
The thought of lost/sunken lands has always fascinated me, beginning with the legendary land of Lyonesse, once believed to be off the coast of Cornwall, between Land’s End and the present Isles of Scilly. It features prominently in the story of Tristan and Iseult. And, like many such sunken lands, the bells of its lost churches are sometimes said to be heard from beneath the water.
Now it has been noticed on the famous Gough Map that there are two islands shown in Cardigan Bay. You can see them in the top illustration. They aren’t to be found there now, but are thought to be the long lost Cantre’r Gwaelod. They’re causing a lot of interest in Wales. Cantre’r Gwaelod was flooded after “the keeper of the gate that kept out the sea, Seithenyn, went to a party, got drunk and forgot to close it”. I wonder if Seithenyn survived and what his ultimate fate was for such dereliction of duty? Can’t have been good. You can read more about Cantre’r Gwaelod at this site and the illustration below is from the same site.
Another famous lost land of Wales is Tyno Helig off the North Wales coast, and you can read about it here.

There are other mysteries, lost lands and strange sites both in Wales and off its coast, but I cannot list them all.
I have to wonder just how much faith we can have in the Gough Map. Yes, some of it is accurate according to the standards of its time), but then it also indicates that the South Devon coast was the landing point for Brutus and his group of Trojans. So caution is required. You can read more about the Map itself here.
On the other hand there are places that have disappeared that are known to have once existed. For example Dunwich off the Suffolk coast, and Ravenspur and its town at the mouth of the Humber, where Henry Bolingbroke and his army landed with the intention of toppling Richard II. (Yes, yes, he said he was only trying to retrieve his rightful patrimony, but in my opinion he was always after the throne itself. But that’s another story.) Edward IV landed there too, and he definitely intended to take back the throne. Both were successful in their aims. Ravenspur has gone due to erosion, and I don’t know of any legend attached to it. Dunwich, of course, was lost in a terrible storm.
One of the above links refers to Atlantis, which is the most famous lost/sunken land of them all. It’s credited with being at Santorini in the Mediterranean, or somewhere in the Atlantic beyond the Straits of Gibraltar, perhaps in Antarctica and maybe another victim of the Bermuda Triangle. But it’s also claimed by some to be off the coast of Ireland! There it is known as Hi-Brasil, and you can read about the latter here.

and here.

There are many more mysterious disappeared lands around the world, and and I don’t know about even half of them. Not even the ones around the British Isles. Nor do I know if they ever truly existed or were simply conjured for exciting yarns around the fire on a winter’s night. I’d like to think they were all real, and that they could brought to the surface again for us to see what they were really like. But I fear the very opposite is more likely, with global warming causing the oceans to rise….thus drowning the underwater lands still deeper.
Australian scientist Patrick Nunn has written two books on lands submerged by rising seas since the last ice age : The Edge of memory and … oh dear, I can’t remember the other! They are very interesting though and written for the general reader, not the scientific specialist.
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The other book by Patrick Mann is Worlds in Shadow : Submerged Lands in Science, Memory and Myth (Bloomsbury Sigma, 2021)
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Whoops! The author is Patrick Nunn, not Patrick Mann! Sorry!
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