Aquae Sulis Western Roman Empire and its urban life declined. However, while the great suite of baths fell into disrepair, some use of the hot springs continued. After the end of Roman rule in Britain around AD 410, some residents seem to have remained, but violence seems to have taken root for, in the 440s, a young girl's severed head was thrust into an oven in Abbeygate Street. As far back as Geoffrey of Monmouth, the Arthurian Battle of Mons Badonicus (c. 500) has been suggested to have taken place near Aquae Sulis. In medieval times, the Roman temple at Bath was
Geothermal energy a renewable energy source like geothermal. But as a result of government assisted research and industry experience, the cost of generating geothermal power has decreased by 25% over the past two decades. In 2001, geothermal energy costs between two and ten US cents per kWh. Hot springs have been used for bathing at least since Paleolithic times. The oldest known spa is a stone pool on China's Lisan mountain built in the Qin Dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. In the first century AD, Romans conquered "Aquae Sulis",