At the very heart of the site is the Sacred Spring. Hot water at a temperature of 460C rises here at the rate of 1,170,000 litres every day and has been doing this for thousands of years. In the past this natural phenomenon was beyond human understanding and it was believed to be the work of the gods. In Roman times a great Temple was built next to the Spring dedicated to the goddess Sulis Minerva, a deity with healing powers.