Archaeologists have discovered what they say is a massive outdoor shrine dating back 4,000 years during excavation work near an industrial estate in Tiel in the heart of the Netherlands.

The “spectacular find” covers some four football fields and was used to make sacrifices, for celebrations and rituals, the archaeologists say.

In total, over one million objects have been found at the site, including glass beads which can be traced back to Mesopotamia. They are the oldest beads ever found in the Netherlands and proof there was contact between the inhabitants of both regions, Tiel town council said.

Work began at the site, on the banks of the river Waal, in 2017, but the size of the location and the huge number of finds has only just been made public.

Archaeologists say there were three earth grave mounds on the site which contained the remains of 80 men, women and children. Some were buried, some had been cremated.

The largest of the mounds is 20 metres in diameter and would appear to function as a solar calendar. It was surrounded by a ditch with several openings where the sun shone on the longest and shortest days of the year.

Some of the items will be on show at the local Tiel museum. Others have been given to the Dutch museum of antiquities in Leiden.

Archaeologists earlier reported finding a large number of Roman artefacts close to the same location.