An unexcavated area of Harappa is rich in deposits.
An enormous amount of work to do, and only a tiny proportion most ancient Indus sites like Harappa, Mohenjo-daro and Dholavira have been excavated.
A small fraction of Harappa has actually been excavated. Most of the site is untouched by the archaeologists tools. It may be that future non-invasive techniques like ground penetrating radar help us map out what remains under the soil.