The Coentunnel (1966) is a tunnel in the A10 motorway under the North Sea Canal in western Amsterdam. The tunnel is named for the 17th-c colonizer Jan Pieterszoon Coen. The tunnel itself is 1283 metres long of which 587 metres are fully covered. The tunnel connects the Zaan district with the western part of Amsterdam. The tunnel reaches a maximum depth of 22 metres. Construction commenced in 1961 and the total cost amounted to 45 million Dutch guilders. The opening of the tunnel was inaugurated on 21 June 1966 by Queen Juliana.