Harecastle Tunnel is a canal tunnel on the Trent and Mersey Canal at Kidsgrove in Staffordshire. It is made up of two separate, parallel, tunnels described as Brindley (2,880 yards or 2,633 metres) and the later Telford (2,926 yards or 2,675 metres) after the engineers that constructed them. Today only the Telford tunnel is navigable. The tunnel is only wide enough to carry traffic in one direction at a time and boats are sent through in groups, alternating northbound and southbound.