A watching brief was held during the construction of a two-storey extension to the rear of No's 16 & 17 Trinity Street. The ground surface was lowered for new floors at which point deep, rectangular, brick-lined cess-pits were located at the north-west and south-west corners of the plot. The lower parts of these were constructed from narrow 16th or 17th century bricks. Dark soil occurred to a depth of at least 2 m and it was assumed that this was the fill of many intercutting pits. No medieval structure of Roman stratigraphy was recovered.<1>