The Roman bathing complex at Bath was completely out of
proportion to the size of the Roman town here. Fed with
naturally hot water from the Sacred Spring it was designed to cater
to the needs not just of local people, but of people who travelled
as pilgrims from across the Empire.
The baths at Bath were unusual not just for their size, but also
for the fact that they used so much hot water. Roman bathing
did not normally use much hot water, as this was expensive to
produce. Instead Roman bathing was based around the practice
of moving through a series of heated rooms culminating in a cold
plunge at the end. This sequence might include an opportunity
to luxuriate in a hot tub or a small bath of hot water in the
caldarium, but it did not involve swimming around in a great hot
swimming pool such as that provided at Bath.

Artist's impression of the bathing complex