Avebury, a Neolithic henge monument is one of the best known prehistoric sites in Britain and contains the largest megalithic stone circle in the world. It is a place of religious importance to contemporary pagans. It is believed rituals would have been performed at Avebury in order "to appease the malevolent powers of nature". Being a henge and stone circle site, astronomical alignments are a common theory to explain the positioning of the stones at Avebury.