Wikipedia
Maeslantkering
The Maeslant Barrier seen from the north
Location of the Maeslant Barrier
A ship passing the barrier
Model (no longer present)
The Maeslantkering closed
The Maeslantkering is a storm surge barrier on the imaginary dividing line between the Nieuwe Waterweg waterway located at Hoek van Holland and the river Scheur located along the cities of Maassluis and Vlaardingen up to the confluence of the rivers Oude Maas and Nieuwe Maas, Netherlands, , which automatically closes when needed. It is part of the Delta Works and it is one of largest moving structures on Earth, rivalling the Green Bank Telescope in the USA and the Bagger 288 excavator in Germany.