Knaresborough Viaduct: The history behind one of Yorkshire's most iconic landmarks

However, the opening was delayed when much of the almost-completed viaduct collapsed into the river on March 11, 1848, the crashing of falling gritstone continuing to be heard in the town centre for five minutes.

Lime in the building mortar which fell into the river was responsible for the deaths of thousands of fish.

Once the debris was cleared from the Nidd, work began on a replacement viaduct with castellated walls and piers designed to fit in with the nearby ruin of Knaresborough Castle.

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With a height of just over 80ft (24.5m), it has four arches and three piers. The total length is 260ft (80m). The architect was Thomas Grainger, a Scottish civil engineer and surveyor.

After costing just under £10,000 to build, the opening ceremony was held on October 1, 1851.

It has long been a tourist attraction and, although the famous architectural historian Sir Nikolaus Pevsner considered it a “notable railway crime”, the Bradford-born novelist and playwright J B Priestley wrote that its reflection in the Nidd “added a double beauty to the scene”.

The viaduct is a grade II-listed structure.