Immediately south-east of the village the canal crosses the valley of the river Great Ouse on an embankment and aqueduct known as the Cosgrove Iron Trunk Aqueduct. The river was initially crossed on the level, with four temporary locks lowering the canal from the south-east, and five raising it from the river towards the north-west (the top lock of these is still in place). The temporary locks were used as a means of getting the canal open to through traffic by 1800 (this river crossing and the tunnel at Blisworth being the only two gaps by that year). However, it was always intended that the river should be crossed by aqueduct, as the locks were wasteful of water, time-consuming and the river in flood in winter could prevent through passage. A brick aqueduct was built, but collapsed in 1808, after which the locks were re-opened. It was replaced by the present Cosgrove aqueduct, built of cast iron, and opened on 22 January 1811. The old lock gates can still be seen beside the footpath below the canal embankment.