The Coentunnel (1966) is a tunnel in the A10 motorway under the North Sea Canal in western Amsterdam.
Before the tunnel was built, the Hem ferry and, to a lesser degree, the Schellingwouder bridge were the most important connections between Amsterdam and Zaandam, and this was a serious bottleneck for traffic.
In the 1950s inhabitants petitioned successfully for a tunnel under the North Sea Canal.
Construction commenced in 1961 and the total cost amounted to 45 million Dutch guilders.
The Second Coen Tunnel has been procured under a public-private partnership structure, and construction started in the summer of 2009.