“They heard of the Great Barrows, and the green mounds, and the stone-rings upon the hills and in the hollows among the hills. Sheep were bleating in flocks. Green walls and white walls rose. There were fortresses on the heights.” 
As well as the barrows and stone-circles of my two previous posts, the Wessex Downs have quite a large number of Iron Age fortresses on the hilltops. The closest of these to Avebury, and the first I visited was Barbury Castle, a few miles south of Swindon.
Barbury Castle is perhaps the most remarkable of the Ridgeway hill forts. It’s on the edge of the Marlborough Downs with views in all directions, on the Ridgeway, and it’s huge! It is defined by a broadly elliptical double rampart with a ditch in between, which even after two millennia of erosion, remains quite steep and imposing. The fort was built in the 6th century BC as a refuge against warring tribes. At times of attack, people would bring their animals and shelter in huts inside the 12 acre enclosure. The outer bank was reinforced by huge sarsen stones and the inner bank was topped by chalk blocks and a continuous wooden fence.
The fortress is clearly visible in this satellite photo, taken from Google Earth Pro, and also just outside the western entrance can be seen a round barrow which dates from 1,700 BC.
I recently had an opportunity to spend a weekend exploring Neolithic, Bronze Age and Iron Age sites on the Wessex Downs. Britain’s “oldest road”, the Ridgeway, runs 87 miles (137 kilometres) across the Wessex Downs eastward to the Berkshire Downs and the River Thames. It has been in use for over 5,000 years and I briefly visited it over 30 years ago.
West Kennet Long Barrow, an early Neolithic grave.
West Kennet Long Barrow
At the western end of the Ridgeway, a couple of miles from Avebury, I visited West Kennet Long Barrow which was built during the early Neolithic period around 3,650 BC. There are five stone burial chambers in the eastern end, and at least 46 people were buried here over a 1,000 year period. The entrance consists of a concave forecourt with a facade made from large slabs of sarsen stones which were placed to seal entry towards the end of its life.
Large sarsen stones guard the entrance to the Barrow