Key Issue: Where was the wheel first manufactured ?
Ljubljansko barje, Slovenia
The Ljubljana Marshes (Ljubljansko barje in Slovenia) is a large wetland area located south of Ljubljana, Slovenia. This unique natural region was the site of one of archaeology's most significant discoveries when, in 2002, archaeologists unearthed what would become known as the world's oldest known wooden wheel, dating back to approximately 3200-3100 BCE. The area was historically a lake during the Ice Age that gradually transformed into a marsh. This marshy environment actually helped preserve ancient wooden artifacts, including the famous wheel and its axle, by creating anaerobic conditions that prevented decay. Beyond its archaeological significance, the Ljubljana Marshes are recognized as an important ecological zone, home to diverse plant and animal species, and the area has been designated as a nature park. The wetland bears evidence of human settlement dating back to prehistoric times, with numerous pile-dwellings (houses built on wooden platforms above the marsh) from various periods having been discovered there. In recognition of its historical importance, the prehistoric pile-dwellings in the Ljubljana Marshes were inscribed on UNESCO's World Heritage List.
Source: Wikipedia
Title: Sewer caps Slovenia