The Great Bath was the centrepiece of the Roman bathing
establishment. It was fed with hot water directly from the Sacred
Spring and provided an opportunity to enjoy a luxurious warm swim.
The bath is lined with 45 thick sheets of lead and is 1.6 metres
deep. Access is by four steep steps that entirely surround the
bath.
On the centre of the north side there was originally a fountain
feature fed by its own lead pipe from the Sacred Spring. At some
point this was replaced with a smaller fountain which is which
is what we see today.
A large flat slab of stone is set across the point where hot
water flows into the bath. It is known today as the diving
stone.
The bath was originally roofed with a pitched timber construction,
but this was replaced in the second century with a much heavier
ceramic vault that required strengthened pillars to support it. The
result was that the original slender pillars were thickened and
projected into the bath itself.
The Great Bath, east end
Artist's impression of the ceramic vaulted
roof