The unusual watercourse at the former Wirral Cadbury factory has been listed at Grade II by the Department for Digital, Culture, Media & Sport on the advice of Historic England.

The listing of the watercourse, which was designed by renowned landscape architect Sir Geoffrey Jellicoe after the Second World War, has been announced alongside the protection of 20 post-war landscapes which have been added to the Register of Parks and Gardens, part of the National Heritage List for England.

The newly announced protections by Historic England are the result of a three-year collaboration with The Gardens Trust. Thanks to suggestions from landscape professionals and members of the public, some of the best examples of landscapes designed between the end of the Second World War and the early 1990s have been identified for protection.

Those highlighted range from memorials, to the grounds of housing estates, institutions and private houses, as well as commercial and industrial sites.

Catherine Dewar, North West Regional Director, said: “Sir Geoffrey Jellicoe’s watercourse at the Cadbury factory delighted passing workers with its cascades and weirs and it’s among many special landscapes given protection today.

"Many demonstrate incredible thought and care for the people who would go on to use them and others mark significant turning points in the history of English gardening.

"This project shines a light on some amazing structures and landscapes that exist all over the country, celebrating how they enhance our lives, and helping to protect them for generations to come."

A modern interpretation of an 18th century ha-ha, the watercourse had a functional and aesthetic role, designed to act as a physical barrier, as well as a decorative feature for employees and visitors to enjoy. The innovative design incorporates a series of weirs or cascades on a site with very flat topography and makes clever use of false perspectives to give the illusion of distance.

It was Jellicoe's first large-scale concrete water feature.