Scammonden Dam, West Yorkshire.

Scammonden Reservoir, also known as Dean Head Reservoir, was created by flooding the Dean Head Valley in the 1960s to provide water for Huddersfield. The reservoir is unique as it carries the M62 motorway on its dam, making it the first and only such structure in Britain. The village of Deanhead, previously located in the valley, was submerged to make way for the reservoir. Before the 1960s, the Dean Head Valley was a thriving area with a village, mills, and a landscape of gritstone and shale formations. The reservoir's construction was part of a larger project to improve transport links between Lancashire and Yorkshire, with the M62 motorway needing a route across the Pennines. The Huddersfield Corporation Act of 1965 authorized the project. The reservoir started filling in July 1969, submerging the village of Deanhead and its buildings. The M62 motorway was built on top of the dam, making it a unique feat of engineering. The reservoir and the motorway were officially opened by Queen Elizabeth II in 1971, with a plaque near the valve tower commemorating the event. The reservoir provides water to approximately 200,000 people in Huddersfield. The area is now a popular spot for recreation, including bird watching, hiking, and mountain biking.