This video from space actually shows the US Army building a mysterious island, Poplar Island, in Chesapeake Bay.
It is about 460 hectares large and aims at restoring the land and deepening the seafloor between the states of Virginia and Maryland.
About 100 years ago, Poplar island’s size diminished from 400 to not more than 10 hectares and composed of three pieces of land. The rest of the island was simply washed away by the sea. But 15 years ago, U.S. authorities approved the financing of a unique project to restore this forgotten piece of land.
The Army started working right away, building dikes and filling the gaps with underwater mud. The evolution of the construction was captured by a NASA landsat satellite and is presented in the following time-lapse video:
This is no secret military facility! It was actually done to solve a transport problem. Indeed, at this time, most of the waterways did not exceed 15 meters in the bay making navigation difficult. So the US government decided to remove a layer of soil from the shallowest parts of the bay (port of Baltimore) and to fill up this island between the states of Virginia and Maryland. So their is no weird stuff happening there.
The work on Poplar Island began in 1998. For the time being, the square of the island makes up 460 hectares. It is now a wildlife sanctuary for birds (including majestic bald eagles!).