The Dutch are world experts in water management and have created masterpieces of hydraulic engineering. There are 3,500 kilometres of primary flood defences (dykes and dunes) in the country and an extensive network, the Deltaworks, was completed with the opening of the Maeslant barrier in 1997. Until recently, Rhine delta river dykes were raised for flood protection, but this centuries-old policy has now been abandoned in some areas. In the ‘Room for the River’ policy, land will (at last) return to nature.