[SunkenCiv]

In the Mabinogeon, the waters between Britain and Ireland are known as the Sinking Lands, an apparent (very ancient) memory of former dry land, now recalled only by the broken-off submerged forests.

[Fred Nerks]

The cliffs on the Aran Islands look as if the land snapped off and fell into the sea...

Dun Aonghasa

GOOGLE.

Reminds me of this image:

ORKNEY link to image

Stone statue at Insishmor, Aran Islands.

WHOOPS!

[Fred Nerks]

LYONESSE LEGEND.LINK.

The Seven Stone Rocks are held to be the remains of a city that local fishermen call The Town, while in Mount’s Bay in Penzance the remains of a sunken forest can be seen at low tide. Lending weight to the legends is the fact that St. Michael’s Mount, in Mount’s Bay itself, has the Cornish name of Carrack Looz en Cooz - literally the grey rock in the wood. Cornishmen around Penzance still believe strongly in a sunken forest in Mount's Bay, and archaeological evidence of the forest is visible at very low tides, where petrified tree stumps become visible.