Here is the Frisian one, and look at those nice "Herculis Columnae" at its entrance:
Another, older name is used for the Frisian Middel Sea: Burdo/Burdinus/Bidurgus : http://en.wikipedia.org/wiki/Middelzee
The island I have been talking about, Wexalia, did not exist yet: it started as a sandbank around 800 AD north of the Middel Sea, got that name, then later on attached itself to a larger island in the west and together they were called "Ter Schelling / Terschelling" from then on.
Schotanus atlas of 1664 / 47 very detailed maps of Friesland
The Netherlands in prehistory:
Edited by Abramelin, 03 November 2011 - 06:01 PM.