the old sarum geophysical survey is being carried out by archaeologists from the university of southampton - and is giving scholars an unprecedented and unique opportunity to more fully understand norman town planning . the results include a series of large structures , possibly defences , with open areas of ground behind possibly for mustering resources or people . old sarum was the original site of salisbury , which is two miles away . the latest scanning techniques were used to uncover a network of buildings at the 11th century old sarum near salisbury , wiltshire . it was the location of the original salisbury , wiltshire image copyright university of southampton image caption students from the university of southampton spent the summer on site what is old sarum ? located inside the massive earthwork defences of an iron age hill fort at old sarum in wiltshire , the medieval city was largely founded by william the conqueror who made it the venue for one of norman england ’s most important political events – a gathering of the country ’s nobility at which all england ’s mainly norman barons and lords swore loyalty to william . so far they have been able to reveal the buried foundations of literally image copyright environment agency university of southampton image caption the inner and outer baileys of the old sarum iron age fort were surveyed a detailed plan of a medieval city has been produced by experts without any digging at the site . archaeologists in southern england have discovered what may be one of the largest medieval royal palaces ever found – buried under the ground inside a vast prehistoric fortress . they concentrated their survey around the inner and outer baileys of what was once a fortification , with its origins in the iron age and the roman conquest.1 their investigations reveal the layout of a settlement including structures from the late 11th century palace was discovered by archaeologists , using geophysical ground - penetrating ‘ x - ray ’ technology to map a long - vanished medieval city which has lain under grass on the site for more than 700 years .