Take a trip through Standedge tunnel
Take a short trip through the longest, highest and deepest canal tunnel at Standedge as surveyors carry out the annual inspection.
The tunnel, on the Huddersfield Narrow Canal, was opened on 4 April 1811.
It stretches through millstone grit for 3.25 miles (5.2km) from Marsden, West Yorkshire, to Diggle, Greater Manchester. It was used by boats carrying wool, coal and horse manure.
Engineers from the Canal and River Trust are surveying for cracks and identifying any restoration work needed.