The dry weather, and no we are not complaining about it however dry the site gets, has helped us identify at least one new feature of potential importance.
You may be able to make out a parched U-shaped profile in the central upper part of the photo. This appears to indicate a construction slot that has dried out differentially to its surroundings. This may be one wall of the building that contains the plaster floor. We will be investigating this over the next day or two in order to trace it in plan and to try and find the other sides.