Grand Junction Canal Nene at Northampton, to the turnpike road at Old Stratford (north-west of the modern Milton Keynes), and to Watford in Hertfordshire: those to Daventry and Watford were not built. The branch to Old Stratford was amended before it was built (see below). The branch to Northampton was delayed as the plans of the Leicestershire and Northamptonshire Union Canal to reach Northampton and thus join with the Grand Junction came to nothing. The link to Northampton was made by a tramroad transferred from Blisworth Tunnel, with the 5-mile (8-kilometre) canal from Gayton being opened in 1815. The link to Leicester was
Greywell Tunnel and so avoid the possibility of closure under the Railway and Canal Traffic Act 1888. Harmsworth, the last trader working on the canal, bought the canal in 1923, but only the lower section up to Woking was used. The tunnel was finally closed when part of the roof collapsed in 1932, after which the canal to the west, including Basingstoke Wharf, was sold. It was still possible for canoeists to get through the tunnel until the late 1950s, but the blockage is now total. The tunnel is of interest for its bat populations: it has more roosting bats than any