The Conservation Project

The interior of main tunnel inside Silbury Hill, taken during the project in June 2007 In 2007 English Heritage commissioned Skanska Civil Engineering to undertake works to stabilise the hill. This project provided a unique opportunity for archaeologists to find out more about Silbury Hill.

Atkinson's 1968 tunnel was re-opened, giving archaeologists a final opportunity to record the inside of Silbury Hill.  The sides of the tunnel were cleaned and recorded using high-resolution photographs.  Environmental samples were taken from archaeological deposits and a remote-controlled filming vehicle was used to record inaccessible areas.  Excavations also took place on the summit.

All the known voids inside the hill, and the crater on the summit, were then re-filled with chalk, using an enormous 1,465 tonnes of material.  The mound has now been restored to as near its original condition as possible.

The entrance to the tunnel, showing the 1968 date stone from Richard Atkinson’s excavation and now in the Alexander Keiller Museum in Avebury The stabilisation project now completed, specialists from English Heritage and seven universities are analysing the excavated material from the project.  This includes the study of artefacts such as flint and antler tools, and further analysis of the biological remains such as insects, pollen and snails. Radiocarbon dating of the archaeological material will also allow us to put specific dates to the various episodes of construction.

Once the results of the project have been published, we may finally be in a position to answer some of our questions about Silbury Hill - How was it built? When was it built? How long did it take to build?

An aerial view showing locations of work on the hill and the work compound © English Heritage