Instagram video transcript

The Netherlands built two rotating arms as tall as the Eiffel Tower, just to stop the sea. This is the Maaslandkering, often described as the largest moving storm barrier on Earth and one of the largest moving objects ever built. It protects Rotterdam, Europe's largest port, from dangerous storm surges coming from the North Sea.

From above, it looks impossible. Two giant steel gates sit open on both sides of the waterway while ships pass between them every day. But when a powerful storm is approaching, everything changes. The system can close automatically when water levels near Rotterdam are expected to rise above 3 meters. No one has to press a button.

The massive gates float out from their docks. And here's the incredible part. The gates are completely hollow on the inside, allowing them to float like giant ships. As the two enormous arms slowly swing toward each other, the gates move into position across the waterway. Then they are filled with water. Thousands of tons of water rush inside, causing the gates to sink to the riverbed and create a barrier strong enough to stop the sea.

Each gate is 210 meters long, and the giant ball joints connecting them are 10 meters across. Within about two hours, the route between Rotterdam and the North Sea disappears. Most of the time, this giant machine does absolutely nothing. It waits, year after year, silent, ready for the one night the sea decides to attack.

The Dutch didn't just build a barrier, they built a sleeping giant. Follow for more Insane Dutch History.