The Ringvaart is a canal in the province of North Holland, the Netherlands. The Ringvaart (Dutch meaning "ring canal") is a true circular canal surrounding the Haarlemmermeer polder and forms the boundary of the Haarlemmermeer municipality.The Ringvaart crosses the A4 Highway by means of an aqueduct. It was built in 1961, making it the oldest aqueduct in the Netherlands. In 2006, construction was completed of two new portions. The new aqueduct is 1.8 kilometres (1.1 mi) long.