It is said that a Roman source mentioned an ‘Infera Insula’ near Britain. (There is a theory that that island later was flooded by the sea and is now the Goodwin Sands.) Please do you of you know which Roman document mentions this ‘Infera Insula’?
For you to peruse:
The Nautical Magazine: A Journal of Papers on Subjects Connected …, Volume 19
Publications of the Surtees Society, Volume 80
Glossarium Antiquitatum Britannicarum has Tanatos
Pomponii Melae De situ orbis libri tres has Panotos
I saw it suggested that Tanatos is not Goodwin, but Thanet, which stands much higher, and its hills may have been used for beacon fires, and the Welsh for “fire” is “tân”, and Welsh is derived from the old Common Celtic. No connection with Greek “thanatos” here.