Feature: World's longest self-closing flood barrier tested in central Netherlands

Photo provided by the Dutch National Water Authority shows people walking by a flood barrier in Spakenburg, the Netherlands on April 10, 2017. A 300-meter self-closing flood barrier, the longest in the world, is built in the historical fishing harbor of Spakenburg in central Netherlands, a latest addition to the low-lying country's innovative approach in flood protection. (Xinhua)