The archaeologists Mark Gillings and Joshua Pollard suggested the possibility that Avebury first gained some sort of ceremonial significance during the Late Mesolithic period. As evidence, they highlighted the existence of a posthole near to the monument's southern entrance that would have once supported a large wooden post. Although this posthole was never dated when it was excavated in the early 20th century, and so cannot definitely be ascribed to the Mesolithic, Gillings and Pollard noted that its positioning had no relation to the rest of the henge, and that it may therefore have been erected centuries or even millennia before the henge was actually built. They compared this with similar wooden posts that had been erected in southern Britain during the Mesolithic at Stonehenge and Hambledon Hill, both of which were sites that like Avebury saw the construction of large monuments in the Neolithic.