It runs from the confluence of the rivers Noord and Lek, and flows west through Rotterdam.
It ends west of the city where it meets the Oude Maas ("Old Meuse"), near Vlaardingen, to form Scheur.
The total length of the Nieuwe Maas (excluding the Scheur) is approximately 24 kilometres (15 mi).
The Nieuwe Maas flows through some of the most densely populated and developed areas in the Netherlands.
However, during the 13th century a series of floods forced the Maas to shift its main course north towards the Merwede.