This 13-km canal unites Little Venice with the Limehouse docks and the Lea valley; 12 locks and 2 tunnels make it possible to overcome a difference in elevation of 26 m. The canal traverses Maida Tunnel (where the crewmen, lying on their backs, made their barges move by pressing their feet against the roof of the tunnel) along Regent's Park, follows a course between the pavilions of the London Zoo and then passes through Camden Lock to pick up the Islington Tunnel.