It was copper galore 4,000 to 5,000 years ago in a settlement in Spain, scientists recently discovered after unearthing ancient remains from the area.

A team from the Universitaet Tübingen found shards and stone tools over an area of around 90 hectares in the central Spanish region of Azután.

The discovery places this previously unknown settlement in the Copper Age, or Chalcolithic period - the transitional era after the Stone Age before humans realized that adding tin to copper produced much harder bronze.

Prior to the findings, scientists hadn't believed that there were many large settlements in this region, since at the time two mountains ranges - between which the River Tajo runs - would have made crossing the river difficult.

However, it seems one large group of people found a way.

Researchers, headed by Tübingen archaeologist Martin Bartelheim, took geomagnetic soundings and plan to compare those results with aerial photographs of the site to identify the size and structure of the settlement.

"With the new finds at Azután, we can confirm that there was intensive copperworking and settlement also in central Spain. Until now, it was thought that such activity was mostly limited to the fertile coastal regions in the south of the Iberian Peninsula," Felicitas Schmitt, a PhD student in the Resource Cultures collaborative research center, said in a statement.

Another nearby at Aldeanueva de San Bartolomé also shows signs of being from the Copper Age. Ancient millstones and weights for nets recently found point to agriculture and fishing. The finds also indicate that the settlement had a division of labor system, which may have led to more sophisticated trades down the road.

The researchers plan to trace the ancient trade routes across Spain via landscape surveys.

"The two regions have similar tombs, burial rites, and objects. So we are working on the premise that rivers and shepherds' paths played an important roles served as lines of communication even then," added PhD student Javier Escudero Carillo, who was not involved in the study.

The findings are preliminary and should be viewed as such until they are published in a scientific journal.