Artist's impression of the enclosed Sacred
Spring
Roman engineers surrounded the hot Spring with an irregular
stone chamber lined with lead. To provide a stable foundation for
this they drove oak piles into the mud. At first this reservoir
formed an open pool in a corner of the Temple courtyard but in
the second century AD it was enclosed within a barrel vaulted
building and columns and statue bases were placed in the Spring
itself. Enclosing the Spring in a dimly lit building in this way
and erecting statues and columns within it must have enhanced the
aura of mystery that surrounded it. Offerings were thrown into the
Spring throughout the Roman period.
Eventually the vaulted building collapsed into the Sacred
Spring itself. We do not know when this was, but it is likely to
have been in the sixth or seventh century. The oak piles sunk into
the mud two thousand years ago continue to provide a stable
foundation for the Roman reservoir walls today.