It has long been speculated the huge man - made structure in mound was an ornate grave or a ceremonial chamber for religious rituals . But expert claims mound was used as lighthouse and harbour to help Neolithic traders navigate post - glacial settlements . Believes southern Britain was a series of islands linked by waterways , channels and swollen rivers , and that Stonehenge was built on land .
It has long been speculated the huge man-made structure in Wiltshire was an ornate grave or a ceremonial hilltop for religious rituals . But expert claims mound was built as lighthouse and harbour to help Neolithic traders navigate post-glacial waterways . Believes southern Britain was a series of islands linked by waterways , channels and swollen rivers , and that Stonehenge was located on coast .