The Port of Rotterdam is the largest seaport in Europe, and the world's largest seaport outside of East Asia, located in and near the city of Rotterdam, in the province of South Holland in the Netherlands. From 1962 until 2004, it was the world's busiest port by annual cargo tonnage. It was overtaken first in 2004 by the port of Singapore, and since then by Shanghai and other very large Chinese seaports. In 2020, Rotterdam was the world's tenth-largest container port in terms of twenty-foot equivalent units (TEU) handled. In 2017, Rotterdam was also the world's tenth-largest cargo port in terms of annual cargo tonnage.

The Rhine–Meuse–Scheldt delta is a river delta in the Netherlands formed by the confluence of the Rhine, the Meuse and the Scheldt rivers. In some cases, the Scheldt delta is considered a separate delta to the Rhine–Meuse delta. The result is a multitude of islands, branches and branch names, in which a waterway that appears to be one continuous stream may have numerous separate names for different sections, e.g. Rhine → Bijlands Kanaal → Pannerdens Kanaal → Nederrijn → Lek → Nieuwe Maas → Het Scheur → Nieuwe Waterweg. Since the Rhine contributes most of the water, the term "Rhine Delta" is commonly used, although this name is also used for the delta where the Alpine Rhine flows into Lake Constance. By some calculations, the Rhine–Meuse–Scheldt delta covers 25,347 km2 (9,787 sq mi), making it the largest in Europe.