Antwerp is on the River Scheldt, linked to the North Sea by the Westerschelde estuary. It is about 40 kilometres (25 mi) north of Brussels, and about 15 kilometres (9 mi) from the Dutch border. The Port of Antwerp is one of the biggest in the world, ranking second in Europe^[5][6] and within the top 20 globally.^[7] Antwerp was also the place of the world's oldest stock exchange building, originally built in 1531 and re-built in 1872.^[8]