The Nieuwe Waterweg, which opened in 1872 and has a length of approximately , was constructed to keep the city and port of Rotterdam accessible to seafaring vessels as the natural Meuse-Rhine branches silted up. The Waterway is a busy shipping route since it is the primary access to one of the busiest ports in the world, the Port of Rotterdam. At the entrance to the sea, a flood protection system called Maeslantkering has been installed (completed in 1997). There are no bridges or tunnels across the Nieuwe Waterweg.