Plateau on Portishead Formation (Old Red Sandstone) © Elizabeth Woodger
The hard, red-coloured sandstone of the Portishead Formation was formed around 370 million years ago in a desert-like environment. Today, these rocks are found on high ground (Black Down and Beacon Hill), within the eroded cores of large geological folds; the same folds that created the Mendip Hills.
The sparsely populated Black Down plateau was the perfect location for a bombing decoy site during World War II. Among other structures, a series of tumps (like that pictured) were built to prevent enemy aircraft from landing. Many of these earth mounds still traverse the plateau today but now they’re hidden by heathland plants such as heather and bracken.
Image part of the ‘Menhir 2023’ collection by Elizabeth Woodger, through the Moments on Mendip project.