Tintern Abbey, on the Welsh side of the River Wye, was founded in 1131 by Cistercian monks, although its Gothic construction dates from the late 13th century.
Most people are unaware of the Grade II-listed Sandfields Pumping Station, which shows how Victorian villages got clean water.
These two 'pagodas' were used to test atomic bomb components in Orford Ness during the Cold War.
This Grade II-listed 18th-century tomb is about a third of a mile (500m) from National Trust-owned Seaton Delaval Hall.
La Petite Ceinture, a former steam train line near Paris, attracts urban explorers drawn to eerie ruins.
Vitalij Bobrovic's moody photo of Bibury, a Cotswolds village, looks spooky.
Between 1850 and 1852, three-gun Stack Rock Fort was built on a small island in Pembrokeshire's Milford Haven Waterway.