EXPERTS have produced a detailed plan of Old Sarum without any digging at the site.

The latest scanning techniques were used to uncover a network of buildings at the 11th Century hill fort, once a thriving medieval city.

A series of large structures, possibly defences, were revealed.

University of Southampton students carried the survey, focusing on the inner and outer baileys of what would have been the fort.

Techniques used included magnetometry, earth resistance, ground-penetrating radar and electric resistivity tomography, which uses electrodes to probe underground.

The university's director of archaeological prospection services, Kristian Strutt, said: "Archaeologists and historians have known for centuries that there was a medieval city at Old Sarum, but until now there has been no proper plan of the site.

"Our survey shows where individual buildings are located and from this we can piece together a detailed picture of the urban plan within the city walls.”

Salisbury Journal:

The city was inhabited for more than 300 years, but declined in the 13th Century with the rise of New Sarum (Salisbury).

The findings reveal series of massive structures along the southern edge of the outer bailey defensive wall.

There is also an open area of ground behind these large structures, perhaps for mustering resources or people, or as part of a circular route through the city.

Residential areas have been identified in the southeast and southwest parts of the outer bailey alongside the inner bailey ditch, and there is evidence of industrial features, such as kilns or furnaces.

Features suggesting quarrying at the site after the city's decline were also discovered.

English Heritage looks after the site.

Property curator Heather Sebire said: “Having the team of archaeologists on site over the summer gave our visitors a chance to find out more about how important historic landscapes are surveyed.

“The use of modern, non-invasive surveying is a great start to further research at Old Sarum.

“From this work we can surmise much about the site's past and, while we can't conclusively date the findings, it adds a new layer to Old Sarum's story.”

The team hopes to return to complete the survey of the inner and outer baileys and survey the Romano-British settlement to the south of Old Sarum at Easter.

Mr Strutt said: “Our research so far has shown how the entire outer bailey of the monument was heavily built up in the middle ages, representing a substantial urban centre.

“Results have given us compelling evidence as to the nature of some of the structures.

“It is clear, however, that there is more non-intrusive work that could be carried out to further expand our understanding of the site.”