On Chester’s busy Bridge street, in the historic centre of the city, a building housing a an everyday fish and chip shop is curiously listed in England’s National Heritage register as a Grade I listed site.
Everything appears normal as you enter and I am certain thousands of people have happily eaten their fish and left without ever realising what lies right beneath their feet.
To the left their is a staircase down to an additional seating area within the cellar. It is in this room that the remains of an original, in situ, Roman hypocaust can be found.
This was an underfloor heating system as part of the legionary baths.
Chester is one of the oldest of English cities – it was founded by the Romans between A.D. 70 and A.D. 80 and they ruled here for over 350 years at the very far end of the Roman Empire.
In Roman Chester the Via Praetoria marked the southern approach to the Roman Headquarters Building, whose front entrance faced straight down what is now Bridge Street. The the upper part of Bridge Street would have been the location of officers quarters, while further down were the legionary baths and the legionary hospital.
The Hypocaust (from the Greek word meaning ‘Fire Beneath’) was a common form of central heating used by Romans. Small pillars of stone or tile supported the floors, and hot air from a furnace was fed through the space beneath, and taken up the side of the building through chimneys. Thus the rooms were kept warm and dry, and the furnace could also be used to heat the water for the baths.
The building, of which the Bridge Street Hypocaust was only a tiny part, was one of the largest in Chester. It is thought to have been the ‘schola’ or officers club, for the men of the Twentieth legion, where they could relax in their off duty hours enjoying a Turkish bath, taking exercise, or merely chatting with their comrades after a hard day.
To make the Bridge Street Hypocaust the Romans cut down into solid rock, and then made a flat surface of concrete on which to set the pillars. Some of this concrete can still be seen on either side of the doorway which leads to the Hypocaust. Notice the many pieces of broken tile which were added to the mix. The pillars themselves are made of local sandstone, and there were originally 32 of them.
The Hypocaust was discovered as long ago as 1725 and there have been many theories to explain the large rock-cut pit which lies to the left of the doorway; some have thought it to be a plunge bath for the Roman baths, but the true explanation is probably that it is part of the medieval cellar system, made over a thousand years after the Hypocaust.