PRELIMINARY work has started on the £150m Silver Hill scheme in Winchester.
Engineers and archaeologists are drilling test boreholes across the site between Friarsgate and The Broadway in the city centre.
The holes will be up to 40m deep to allow archaeologist consultants PCA to build up a picture of what lies under the surface.
Developer Henderson has submitted its revised planning application to the city council. It wants to build flats and shops and drop plans for a new bus station and offices.