The Archaeological Research

An opportunity to increase our understanding

Cut-away diagram of the hill
© English Heritage
 The stabilisation work at Silbury Hill provides an unprecedented opportunity to carry out archaeological recording and investigation, in an attempt to answer some key questions:

The turf in the primary mound
© National Trust
 1. How was Silbury built [1]?

The enormous monument we see today covers two much smaller mounds. The first was a circular mound of turf and gravel [2]. This was enlarged with alternating layers of soil and chalk to create a second mound [3]. These were then buried beneath the massive chalk mound, itself possibly built in two major stages [4]. Further information on this construction sequence will help us to understand the engineering skills and techniques of the builders.

Striped layers of the second mound
© National Trust
 2. When was Silbury built?

Radiocarbon dating shows that building Silbury began at some time between 2445 and 2190 BC, and probably around 2300 BC. We hope to find new organic material that will provide a more precise date.

The final chalk mound
© National Trust
 3. How long did Silbury take to build?

Radiocarbon dating has provided us with two possible time spans for the construction of the Hill – less than 115 years, or between 140 and 435 years. Finding new organic material from the top and bottom of the Hill should allow us to establish this chronology more accurately.