As I mention later on the Ribe page, much of south-western Denmark is protected by a series of locks, dikes and seawalls.
Interesting European language tidbit. The word for "lock" (wrt the water kind of lock, no the one on your door!) is the same in Danish and Dutch. I learned this from my host dad, Ole, who was once attempting to express the concept of a lock in Holland, and well, it just sort of worked out.
Adam can be reached at adam dot morley at gmail dot com