Does Medieval Map Reveal Location of Wales’ Sunken Atlantis?

New research has revealed evidence of two lost islands off the Welsh coast. The islands might be the source of the legend of Cantre’r Gwaelod — an Atlantis-like myth that has persisted in Welsh culture for a thousand years.

a landscape view of a coastline in wales

The coastline of Cardigan Bay, Wales. Photo: Cliff Day/Shutterstock


Simon Haslet of Swansea University and David Willis of Oxford noticed the islands when they examined the Gough Map. The earliest surviving complete map of the British Isles, it dates to around 1360 AD.

Known for its accuracy (especially for the time), the map indicates two islands off the Ceredigion coast in Cardigan Bay that do not exist today. The two professors theorized that Holocene sea-level rise and various types of erosion probably destroyed the islands by the 16th century. They published their findings in the journal Atlantic Geoscience.

The Gough Map. Photo: Public domain


In an interview with the BBC, Haslet said, “The two islands are clearly marked and may corroborate contemporary accounts of a lost land mentioned in the Black Book of Carmarthen.”

In this version of the Cantre’r Gwaelod myth, the islands were lost to flood when a well-maiden allowed her well to overflow.

According to the National Library of Wales, the Black Book of Carmarthen is “the earliest surviving complete manuscript written in the Welsh language.”

a map showing the locations of the islands. Text reads "approximate locations of the islands as indicated by the Gough Map.

Approximate locations of the islands as indicated by the Gough Map, near present day Aberystwyth and Barmouth, Wales. Map: Google Earth

An enduring myth; no geological evidence

A version of the Atlantis myth pervades many European cultures. The classic telling springs from an allegory in the works of Plato, and variations appear in early Christian and Jewish works. Renaissance writers such as Sir Francis Bacon and Thomas More later revived Atlantis as a sort of Utopia, and popular culture has kept it alive ever since.

Of course, one place where the sunken city has not appeared is on planet Earth. That remains true despite Haslet and Willis’ findings. The islands may appear clearly on the Gough Map, but they’re nowhere to be found now.

Andrew Marshall

Andrew Marshall is an award-winning painter, photographer, and freelance writer. Andrew’s essays, illustrations, photographs, and poems can be found scattered across the web and in a variety of extremely low-paying literary journals.
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