sentences:  In the second half of the 20th century it was recognized that there were other sites in the neighbourhood, now labelled 
  Kostenki-1 to Kostenki-21 and Borshchevo-1 to Borshchevo-5.The most famous of these are Kostenki-12 (Volkovska) and Kostenki-14 (Markina Gora).A 25,000-year-old bone circle structure of at least 60 mammoths, measuring over in diameter, was discovered at Kostenki in 2020.