Housesteads Roman Fort, Vercovicium, AD 124, Granary showing provision for underfloor heating, Hadrians Wall, UNESCO World Heritage Site, Northumbria National Park, Northumberland, England, United Kingdom, Europe

Granary showing supports for ventilated floor and circular furnace to provide heated air underfloor, Housesteads Roman Fort, Hadrians Wall, UNESCO World Heritage Site, Northumbria, England, United Kingdom, Europe

The floor of the Granary showing the underfloor hypocaust heating system, in the Roman Town at Corbridge, Hadrians Wall area, UNESCO World Heritage Site, Northumbria, England, United Kingdom, Europe

Roman remains at the Roman town of Conimbriga in Portugal

Construction of a hospital, laying an underfloor heating, Gelsenkirchen, North Rhine-Westphalia, Germany

Construction of a hospital, laying an underfloor heating, Gelsenkirchen, North Rhine-Westphalia, Germany

Construction of a hospital, laying an underfloor heating, Gelsenkirchen, North Rhine-Westphalia, Germany