Mount Caburn near Lewes was once home to a prehistoric hillfort built around 400 BC. Archaeologists discovered over 140 storage pits, pottery, tools, and ritual burials — evidence that this was a place of ceremony and community, not just defence. From its summit, you can see Firle Beacon and the Ouse Valley, part of a network of hillforts that appeared across Britain during the Iron Age. Only earthworks remain today, but they mark one of the oldest human sites on the South Downs. Location: Mount

4,000-Year-Old Durrington Walls: Britain’s Largest Prehistoric Monument

Stonehenge