Country diary: The underground secret by Hadrian's Wall | Country diary

Coventina's Well, Northumberland: The source of this spring was once encased in a temple and showered with giftsThe Roman fort of Brocolitia, once a busy garrison of 500 soldiers, is visible only as turf-covered earthworks close to Hadrian's Wall. We walk round the perimeter of its playing-card shape, the rain clearing to leave letterbox flares of light along the horizon. There's the harsh "yark" of a solitary crow. A farmer on a quad bike gathers sheep with his dog, the flock rippling over the slope of a far field.Beyond the fort is the Mithraeum, an excavated temple dedicated to Mithras, the Roman god of light, which is preserved in a fenced-off enclosure. Nothing, though, marks Coventina's Well, the spring of a water goddess important enough for the high-status title of Augusta, yet unknown before the well's discovery in 1876. Continue reading...