Fancy an otherworldly experience? The ground beneath our feet hides a multitude of jaw-dropping sites and an underground tour can reveal so much about England’s history and the formation of the English landscape. There are miles of caves to explore, boasting awe-inspiring stalagmites and stalactites. Take a sewer tour – yes, really – to gawp at the subterranean architecture and marvel at Victorian ingenuity. For a less aromatic experience, disused coal mines now offer the chance to descend 140m underground on a mine tour to confront the vivid realities faced by the men, women and children who have toiled in them through the ages. These are hidden gems indeed.