This is the point at which hot water that was not required for
use in the bathing establishment flowed from the Spring into the
great Roman drain. From there it was carried to the River
Avon a few hundred metres away.
The water flows through a sluice that could be regulated to
completely drain the Sacred Spring and give access to the reservoir
chamber for maintenance. The same system devised by Roman
engineers continues in use today, nearly two thousand years after
it was first built.