You might find this interesting. It was cited by the American Society of Engineers as one of the seven modern wonders of the world.
Netherlands North Sea Protection Works
This singularly unique, vast and complex system of dams, floodgates, storm surge barriers and other engineered works literally allows the Netherlands to exist. For centuries, the people of the Netherlands have repeatedly attempted to push back the sea, only to watch brutal storm surges flood their efforts, since the nation sits below sea level and its land mass is still sinking.
The North Sea Protection Works consists of two monumental steps the Dutch took to win their struggle to hold back the sea. Step one, a 19-mile-long enclosure dam, was built between 1927 and 1932. The immense dike, 100-yards thick at the waterline, collars the neck of the estuary once known as Zuiderzee. Step two, the Delta Project, was intended to control the treacherous area where the mouths of the Meuse and Rhine Rivers break into a delta. The project's crowning touch was the Eastern Schelde Barrier, a two-mile barrier of tell gates slung between massive concrete piers, which fall only when storm-waters threaten. The North Sea Protection Works exemplifies the ability of humanity to exist side-by-side with the forces of nature.
Over 25% of the Netherlands is below sea level. The balance of land averages only 37' above sea level. Much of the land that was once below sea level is today reclaimed and protected by 1,500 miles of dikes.
Pretty amazing. But it is only a matter of time before some natural disaster brings it all down.