Brittenburg

Brittenburg was a Roman ruin site west of Leiden between Katwijk aan Zee and Noordwijk aan Zee, presumably identical to the even older Celtic Lugdunum fortress. The site is first mentioned in 1401, was uncovered more completely by storm erosion in 1520, 1552 and 1562, and has subsequently been entirely eroded away. When built, it was located at the mouth of the Oude Rijn (old river Rhine), which has since moved. The site was about one kilometre (5⁄8 mile) west of the European Space Research and Technology Centre, now offshore in the North Sea.