It's a remarkable feat of engineering how much land they've managed to reclaim by building dikes, but it might not be a sustainable solution nowadays. To update that tradition, the Maritime Research Institute Netherlands (MARIN) is testing the concept of an artificial floating island.

MARIN's floating island is made up of large triangles that connect to each other in a modular fashion. Structurally, it works like the Italian Floating Piers and walkways we saw last year, but on a much bigger scale: MARIN says that floating islands built in this way could be as big as 5 km (3.1 miles) wide, and used for a variety of purposes.

"As sea level rises, cities become overcrowded and more activities are carried out at sea, raising the dikes and reclaiming land from the seas are perhaps no longer an effective solution," says Olaf Waals, project manager of MARIN's floating islands.