Feel the ancientness! Just north of the city of Salisbury sits the site of Old Sarum hill fort and castle. From Wiki:

The site contains evidence of human habitation as early as 3000 BC. Old Sarum is mentioned in some of the earliest records in the country. It is located on a hill about two miles north of modern Salisbury adjacent to the A345 road.

Old Sarum was originally an Iron age hill fort strategically placed on the conjunction of two trade routes and the River Avon. The hill fort is broadly oval in shape, 400 metres (1,300ft) in length and 360 metres (1,180ft) in width, it consists of a double bank and intermediate ditch with an entrance on the eastern side. The site was used by the Romans, becoming the town of Sorviodunum. The Saxons used the site as a stronghold against marauding Vikings, and the Normans built a stone curtain wall around the Iron age perimeter and a centrally placed castle on a motte protected by a deep dry moat. A royal palace was built within the castle for King Henry I and subsequently used by Plantagenet monarchs. A Norman cathedral and bishop’s residence were built at the western end of the town.

In 1219, the cathedral was demolished in favour of the new one built near the river and the townspeople moved down to the new city, then called New Salisbury or New Sarum. The castle fell out of use and was sold for materials by King Henry VIII.