Question: Where in the world can you find the oldest manmade structure which was constructed by prehistoric humans 23,000 years ago? Greece is filled with ancient sites and ruins, but perhaps the most remarkable is Theopetra Cave in Meteora, Greece where the oldest known manmade structure on Earth is found.

Meteora, located in Thessaly, Greece, is famous for its unique rock formations and its monasteries perched atop vertical peaks. Meteora which translates to 'suspended in the air' in Greek, is a valley formed about 60 million years ago with the weathering away of the rocks to form columns and spires of rock.

Theopetra Cave contains one of the longest archaeological sequences in Greece, comprising Middle and Upper Palaeolithic as well as Mesolithic and Neolithic cultural remains. The records have shown important palaeoenvironmental data based on sedimentary features and botanical remains.

The Meteora (/ˌmɛtiˈɔːrə/; Greek: Μετέωρα, pronounced [meˈteora]) is a rock formation in the regional unit of Trikala, in Thessaly, in northwestern Greece, hosting one of the largest and most precipitously built complexes of Eastern Orthodox monasteries, second in importance only to Mount Athos.