Silbury Hill is an ancient artificial earthwork and chalk mound near Avebury in the English county of Wiltshire. It is part of the Stonehenge, Avebury and Associated Sites UNESCO World Heritage Site. At 37 metres high, Silbury Hill which is part of the complex of Neolithic monuments around Avebury, which includes the Avebury Ring and West Kennet Long Barrow is the tallest prehistoric human-made mound in Europe and one of the largest in the world; it is similar in size to some of the smaller Egyptian pyramids of the Giza Necropolis. Its original purpose however, is still highly debated. Several other important Neolithic monuments in Wiltshire in the care of English Heritage, including the large henges at Marden and Stonehenge, may be culturally or functionally related to Avebury and Silbury. For scale, noted the several figures on the summit.