Builders have discovered an 2,500-year-old settlement in Pocklington, East Yorkshire during work on a housing development.
A spokesman for the developers David Wilson Homes said the site is of "national and international significance".
It is hoped the "hugely important" discovery will provide the largest study of an Iron Age population in the last 35 years.
Objects including a sword, shield and 10 spears, have already been found during the excavation at the site.
In addition to the weapons, more than 360 amber and glass beads, brooches and ancient pots have also been discovered.
The site includes more than 75 square barrows that contained skeletons from the Arras Culture - a group of people who lived in the region in the Middle Iron Age as far back as 800BC.
Archaeologists will be carrying out analysis in a bid to reveal how those buried at the site died, what stresses the body had been placed in during their lifespan and whether or not they are related.
Paula Ware, managing director at MAP Archaeological Practice, said: "To date, the east of Yorkshire has the largest concentration of 'Arras Culture' square barrows, and naturally these findings have helped to strengthen this."
David Wilson Homes found the settlement at its Pavilion Square development after it started work in September 2014. The discovery will be officially announced on BBC Four's Digging for Britain on Thursday.
Peter Morris, development director at David Wilson Homes, said: "At present we are still at the early analytical stages of reviewing these findings, however we do understand that this discovery is very rare and of international importance."