Bacho Kiro cave

The Bacho Kiro cave () is situated west of the town Dryanovo, Bulgaria, only away from the Dryanovo Monastery. It is embedded in the canyons of the Andaka and Dryanovo River. It was opened in 1890 and the first recreational visitors entered the cave in 1938, two years before it was renamed in honor of Bulgarian National Revival leader, teacher and revolutionary Bacho Kiro. The cave is a four-storey labyrinth of galleries and corridors with a total length of , of which are maintained for public access and equipped with electrical lights since 1964. An underground river has over time carved out the many galleries that contain countless stalactone, stalactite, and stalagmite speleothem formations of great beauty. Galleries and caverns of a long section have been musingly named as a popular description of this fairy-tale underground world. The formations succession: "Bacho Kiro’s Throne, The Dwarfs, The Sleeping Princess, The Throne Hall, The Reception Hall, The Haidouti Meeting-Ground, The Fountain and the Sacrificial Altar".
The site has yielded the oldest human remains ever to be found in Bulgaria. Among one of the earliest known Aurignacian burials (layer 11), two pierced animal teeth were found and ordered into the distinct "Bachokiran artifact assemblage". Radiocarbon dated to over 43,000 years ago, they currently represent the oldest known ornaments in Europe. With an approximate age of 46,000 years, human fossils consist of a pair of fragmented mandibles including at least one molar. Whether these early humans were in fact "Homo sapiens" or Neanderthals was disputed until morphological analysis of a tooth and mitochondrial DNA of bone fragments established that remains were those of "Homo sapiens". In samples F6-620 and AA7-738 identified mitochondrial haplogroup M, in samples WW7-240 and CC7-335 determined the mitochondrial haplogroup N, in sample CC7-2289 identified mitochondrial haplogroup R, in sample of BK-1653 identified mitochondrial haplogroup U8.
A study on remains found at Bacho Kiro cave concluded that Upper Palaeolithic humans had Neanderthal ancestry, which corroborates the link between the earliest modern humans in Europe and later people in Eurasia.