Archaeologists have found a late Bronze age Mycenean harbour town so well-preserved that the entire layout of the buildings and street is clearly visible.

This is hugely rare, unique even. Most towns from this period (about 3,500 years ago) have long since crumbled under layers of dirt and subsequent usage. Korphos-Kalamianos, however, is above ground (and partially under water).

It seems to have been a military outpost. There is no evidence of agriculture, and the grid pattern of the town suggests it was built all at according to a plan.

“Usually to excavate Mycenaean buildings you have to dig underground,” Pullen told LiveScience. “What we have here is the plan of an entire town preserved for us. We have the fortification wall, we have all these buildings, and we can often see where the doorways would be. We can see how the buildings relate to each other, because we have obvious alleyways and streets.”

When Pullen and his team first inspected the walls at the site, they counted more than 900 of them, he said.

The structures are mostly aligned along a grid, leading scientists to think the city was built all at once, as opposed to gradually over time, which would likely result in a more random arrangement of buildings.

“We think it was built for a specific purpose,” Pullen said. “We have evidence that there were a few people at this site for a long time before. Then at some particular point people came in and established this as a new outpost or maybe a naval or military base. And they brought their engineers and builders with them and constructed the main part of the site all at once.”