The Palmschleuse in Lauenburg is the oldest lock in Europe. It was built in 1398 along with the Strecknitz-Canal completely made of wood and had one (out of 15 locks that first watershed channel in the world of construction 1392-1398). Since the Middle Ages, the gate was also known under the name of key to Bockhorst. In the 17th Century, she got its present name after the former lock keepers Palm. In 1724 the gate was rebuilt and lined with hewn stone in its present form. The lock is no longer in operation.