The tunnel at Standedge beneath the Pennines on the Huddersfield Narrow Canal is 194 m below ground level at its deepest point, and is 4951 m long, the longest in Britain. The engineer for the canal was Benjamin Outram (1764-1805), but it was completed, after his death, with advice from Thomas Telford (1757-1834). The navvies driving the tunnel from each end met in 1809, and it was opened for navigation in 1811. Subsequently three railway tunnels were driven through mountain parallel to the canal tunnel in 1848, 1871 and 1894. The last commercial vessel plied along this section of the Huddersfield Narrow Canal in 1921. The tunnel was formally closed to boats from 1943, but vessels did occasionally venture through at their own list. The canal has now been restored and the visitor centre at Marsden at the eastern end of the tunnel provides interpretation of the waterway and the landscape. A transhipment warehouse built in 1798 houses an exhibition on the history of the canal and the tunnel, while a café and the booking office for boat trips into the tunnel are housed in cottages that were once the homes of maintenance workers. The centre is 0.8 km west of Marsden station on the railway from Huddersfield and Leeds to Manchester, which is accessible along the canal towpath. Close to the station is the entrance to the National Trust’s Marston Moor estate, which is rich in wildlife and in archaeological evidence of most periods of history.