This collection comprises reports, images, and plans from a watching brief conducted during piling for the new Corn Exchange extension and an intermittent informal watching brief during subsequent works at North Square, Dorchester, Dorset between 2021 and 2022.

Terrain Archaeology carried out archaeological observations and recording during the piling for a new extension and associated services. The piling observations revealed that the natural chalk was below a layer of probable post-medieval garden soil, buried by terrace deposits for the nineteenth century Market House. A well of possible medieval date was adapted by the addition of a chute in the post-medieval period, perhaps to adapt it as a drain or soakaway within the Market House. A series of post-medieval cellars was also recorded.