Аренсбург

Ahrensburg's castle was completed in 1585 for Peter Rantzau. The associated church and Gottesbuden almshouses followed; the latter continue to provide social housing. Heinrich Carl Schimmelmann bought the estate in 1759. His wealth included proceeds from the transatlantic slave trade, a history that must accompany discussion of his ownership and local patronage. The castle opened as a museum in 1938 and, after wartime closure and renovation, resumed continuous museum use in 1955.

The nearby Tunneltal was formed by meltwater towards the end of the last Ice Age. Archaeological excavations by Alfred Rust in the 1930s recovered stone, wooden and bone implements associated with late Palaeolithic reindeer hunters. The protected valley combines this archaeological importance with wetlands, meadows and woodland habitats.