Fort aan de Drecht, which is located south of Amsterdam, just outside the town of Uithoorn, is a military installation that's more than 100 years old. Upon its completion, the fort was considered a testament to Dutch ingenuity in the field of hydraulic engineering.
Parting the waters to defend the Netherlands
Fort aan de Drecht was built to defend the locks and dikes located
along the Drecht and Kromme Mijdrecht rivers. It was once capable of
flooding the surrounding area, thus protecting the adjacent
communities from foot soldiers and land-based military vehicles.
Unfortunately, the development of advanced flight rendered it obsolete
by the beginning of World War II. The fort is now on the UNESCO World
Heritage List. It was refurbished in the late '90s and opened again to
the public for tours since 2000.