Monument record 8670 - Third Century Roman Building, Frodsham Street South

<1> Earthworks Archaeological Services, 2017, New Drainage Works in Frodsham Street, Chester: An Archaeological Watching Brief, R4041 (Client Report). SCH8276.

As part of a wider programme of refurbishment, new subsurface drainage facilities were required to serve Frodsham Street, Chester. Between August 2016 and February 2017, the groundworks for this drainage were subject to an archaeological watching brief, as it is known that the current line of Frodsham Street overlies the Roman legionary parade ground of the first century AD.

The initial phase of the watching brief, towards the southern end of the new drainage trench, revealed basements to a terrace of 19th century properties (see …..) that once extended eastwards out into Frodsham Street prior to the widening of the street in the mid-20th century; these basements had truncated earlier deposits. However, once the groundworks passed the northernmost and final basement, at a distance of approximately 23m north of the Frodsham Street junction with Foregate Street, in situ archaeological deposits were immediately encountered, including a stone surface interpreted as that of the Roman legionary parade ground (see 8028/5). Overlying this was up to 0.3m of silt deposits containing pottery dating to the mid to late second century AD. Set into the silts was a red sandstone slab surface interpreted as the floor of a structure. This surface was traced for a distance of circa 3.8m north-south and was approximately 1.30m below current ground surface. The slabs measured up to 0.15 by 0.65 by 0.90m and are thought to have been robbed from a a building of some status, scale and importance within the legionary fortress. No evidence for masonry walls was found, but a circular post hole lined with clay and stone packing materials, located at the south-west corner of the sandstone slab surface, indicate a timber construction. The centre of the posthole contained a postpipe filled with grey silt suggesting that the timber post had been removed rather than having rotted in situ. Extending to the east of this structure were metalled surfaces, comprising red sandstone fragments, cobblestones, pebbles, fragments of Roman ceramic building materials and also pottery of circa late second to mid third century date. The function, scale and character of this structure and surrounding metalled surfaces remains uncertain, but pottery and coins retrieved from the grey sand-silt deposit which sealed them, suggest abandonment had occurred by the late third or fourth century.