A piece in the Telegraph suggests (n regards to Silbury Hill), inter alia:
So the mound wasn’t simply some ghostly feature that became abandoned in prehistoric times, says Rob Harding, the English Heritage project manager for the site. According to Harding, there is also evidence of Roman usage in the platforms along the side of the hill. “Often, the Romans adopted the local gods and forms of worship when they arrived in new countries, so we think it would have had some sort of ceremonial function for the Romans. But it is possible it was disused in the period prior to their arrival in 43BC. The Roman road to Bath (the A4) runs around the base of the hill, but we have nothing to suggest it was in use after the Romans until the late Saxon or earlyNorman period.”
Actually, back in 2007, archaeologists found remains of a substantial Roman settlement at the base of the hill. According to a Guardian article from the time:
It was already clear that the Romans knew Silbury – the largest prehistoric structure in Europe, nearly 40 metres high and estimated to have taken 35m baskets of chalk to build – because their ruler-straight road, which the A4 follows, jinked to avoid it.
However the revelation that regularly laid out streets and houses of a village the size of 24 football pitches lay hidden under the modern road and the fields around it astonished the scientists, who were surveying the site before restoration work on the hill.
Bob Bewley, regional director of English Heritage, speculated that Silbury may have been an overnight stop on the way to the sacred springs and bathing pools at Bath, but may also have been a Roman pilgrimage site in its own right.
… and even back then there was this ‘ceremonial’ bent to the interpretation (I think this was also said by the aforementioned Bob Bewley):
“Given the sacred value we know Romans attached to sites close to water it seemed impossible that they would not be drawn in the wake of their prehistoric forebears to Silbury Hill, which lies close to both the Winterbourne River and the Swallowhead springs. To have found such a substantial and organised settlement though is amazing.”
I can’t, however, find any mention of remains of a Roman shrine or evidence of votive offerings or whatever … is there any material evidence to back up this ‘ceremonial’/'sacred’ claim?