Bartlow Hills in South Cambridgeshire. The highest mound is around 40 foot tall
The largest burial mounds north of the Alps are right here in Cambridgeshire.
Bartlow Hills dates back to the early Roman times and were built by important and fabulously rich Iron Age Celtic chiefs.
The mounds were rediscovered in the 19th century and excavations revealed a cremated body and rich artefacts.
Some of the objects were decidedly saucy by 21st century standards, according to Stephen Macaulay, Oxford Archaeology senior project manager.
He said: "The Romans were into interesting - how shall I say? - sexual objects!
"But most of artefacts were lost in a big fire at Bartlow Hall."
The ancient burial mounds as they were seen in an old engraving
The burial mounds are also known as barrows and they were built sometime between the 1st and 2nd centuries AD.
There were initially two rows of the hills but by the time they were excavated between 1815 and 1840 there were only four barrows left.
Large wooden chests with iron fittings were found and a cremated body was also discovered, alongside richly decorated vessels of bronze, glass and pottery and an iron folding chair.
Many of the goods were imported from Europe.
Although most of the objects were lost in a fire, we know what they were like because the finds were written up in various archaeological publications.
A guided walk of the site organised by Cambridgeshire Archaeology
The highest of the hills is 40 foot (15 metres) tall, but these days the site is shrouded by trees and it is easy to miss them.
"They are truly astounding. You wouldn't expect it," said Stephen Macaulay. "They are huge and if you consider that a whole bunch of them have disappeared over the years quite where they've gone and how they've gone is something to be investigated."
So if you fancy exploring Cambridgeshire's massive mounds, wondering who might have built them, then head to the tiny village of Bartlow.