The towpath now goes under three large road bridges. Two M1 feeder roads and in the middle the rather elderly looking bridge 6B carrying the motorway just after Lock 12. Off on the right you'll then see a sign welcoming road travellers to Northampton. The warehouses that blot the East Midlands landscape belonging to Morrisons, Blacks, Levis, Pets R Us et al are in full view from Lock 13 and its reinstated lift bridge.
The canal runs parallel to the A5123 and crosses the Swan Valley aqueduct where the towpath is newly laid and a housing estate appears next to it. Before reaching Lock 14 you pass the Wooton Lock Narrows, the first of three narrows before Hardingstone Lock 15. The canal is so narrow along this whole stretch that if I was on a boat, I really wouldn't want to see one coming the other way.
Although the new towpath stopped at Banbury Lane and you walk between another housing estate and warehouses, it's quite pleasant and there is large expanse of water in front of the latter. The path improves after Upton Valley Way and bends towards the town under bridge 9B following the River Nene with the Lift Tower in the distance. This listed 418ft structure, also known as the Northampton Lighthouse, was opened by the Queen in 1982. One of only two in Europe it's used for R&D by lift companies.
The country park that had been on the other side of the canal is now replaced by Briar Hill Meadows and, although you can't see it, Duston Mill Reservoir and a nature reserve. The towpath is very good until bridge 13 where it virtually disappears and Northampton appears.
You still feel you have one foot in the country, even taking in account the unremitting traffic noise up until Lock 16 and the adjacent railway bridge. Now a high fence, brick wall (built as a flood defence) and notices featuring guard dogs herald an urban landscape.
After bridge 17 the towpath is well paved with adjoining apartment blocks opposite the very large Carlsberg brewery. Following the Northampton Lock Narrows, there's what looks like a filled in branch doubling as a winding hole and a crane refurbished by Bellway Homes that stands in its original position but is now abandoned again in the undergrowth and unkempt surroundings.
Next to to the crane is Northampton Lock where the Grand Union ends and becomes the Nene Navigation. An interesting walk with plenty of locks and adjacent countryside that, while not bucolic, makes the constant traffic noise bearable.