After the disastrous storm surge of 1953, many sea-arms of the delta in the Southwestern Netherlands were closed off by dams and enormous storm surge barriers that are only closed during dangerously high water levels. The marker on the map is located on the artificial island Neeltje Jans, which is part of the 8km long Oosterscheldekerng (Eastern Scheldt barrier). A visitor centre is located there. Other impressive parts of the Deltaworks are the Haringvliet sluices (51.8338N,4.0514E) and the Nieuwe Waterweg barrier (visitor centre 51.9568N,4.1675E) with gates as large as the Eifel tower.
3.7093 E, 51.6374 N