The first representation we have found of the market hall is on Thomas Thorpe's map of 1752 - A plan of the lands belonging to the Right Honourable the Earl of Powis in the manor of Liswerry and Libennith in the parishes of Christchurch, Caerleon, Llanvrechea, etc. We have redrawn the part of the map which is of interest to us here with the market hall marked in red. (The position of the bridge will help with orientation.)

A redrawing of Thomas Thorpe's map of 1752. The market hall is coloured red.
North is at the bottom.

William Coxe visited Caerleon in 1800 making notes for his book(s) An Historical tour in Monmouthshire. Of course he was mainly interested in the Roman remains, so his only observation concerning the Market Hall was: "The four columns of freestone which support the market-house probably belonged to some Roman structure". His book(s), published in 1801, contained a detailed plan of the town showing the location of the market hall.

Section of the plan of Caerleon from Coxe's Historical Tour in Monmouthshire, published in 1801.
The market hall is indicated by the number 3.

When the Priory came up for auction in 1838 the sales particulars included a plan (below) which indicated the position of the market hall.

Section of the plan included in the sales particulars of the Priory in August 1838.

The 1840 Tithe map (below) has the market hall numbered 9a. The apportionment document reveals that it was owned by Sir Digby Mackworth and 'occupied' by Thomas Gunter, also that its area was 4 perches - approximately 100 square metres. The building appears to be twice as long as it was wide making it approximately 14 metres by 7 metres. Thomas Gunter occupied several other properties including the White Hart Inn and the Round Table (amphitheatre) field. (See the 1840 Tithe Map of Caerleon and the apportionment.)

Part of the 1840 tithe map. The market hall is numbered 9a.

Within ten years of the map above being made the Market Hall was demolished.

Drawing of the Market Hall in 1814 - click here.