The Middle Ages, or medieval period, lasted approximately from the 5th to the late 15th centuries.

This hoard of medieval treasures included a sandal, constructed from a type of thick grass called esparto grass, made 674 years ago in the late 14th century.

Other items made from the grass included part of a slingshot and a piece of basket.

The team also found a 650-year-old decorated piece of sheep leather, a crossbow bolt, a piece of a slingshot and other historical items.

It seems the bearded vulture nests have played a big part in preserving these items.

“Thanks to the solidity of bearded vulture nest structures and their locations in the western Mediterranean generally in protected places such as caves… they have acted as natural museums, conserving historical material in good condition,” the study authors report.