A 16th century miniature plan of a Roman fort

A scarce plan of a Roman fort in the sands off Katwijk aan Zee in Holland, discovered when violent storms exposed them in 1520. When the ruins were uncovered again in 1562 they were visited by Abraham Ortelius, who sketched a map before the tide covered the fort over again. The fort, possibly a lighthouse because of its square layout, is now half-a-mile out into the North Sea, unreachable for modern archaeologists.
The plan was engraved by Pieter van den Keere for the 'Caert-Thresoor', with a text by an unknown author.
By 1600 this map was being published in the 'Tabularum Geographicarum Contractarum' with a text by Petrus Bertius, and in 1616 a new plate was engraved by Jodocus Hondius II, slightly larger and with wider borders with scales of longitude and latitude.