- Aerial photographs of Russia's Caucuses Mountains were taken in the 1970s.
- Archaeologists recently spotted stone structures in the photographs.
- They traced the location of the sites at high altitudes and began excavation.
Traces of a previously unknown Bronze Age civilization have been discovered in the peaks of Russia's Caucasus Mountains thanks to aerial photographs taken 40 years ago, researchers said Monday.
"We have discovered a civilization dating from the 16th to the 14th centuries B.C., high in the mountains south of Kislovodsk," in Russia's North Caucasus region, Andrei Belinsky, the head of a joint Russian-German expedition that has been investigating the region for five years, said.
He said researchers had discovered stone foundations, some up to a meter (3.3 feet) high, at nearly 200 sites, all "visibly constructed according to the same architectural plan, with an oval courtyard in the center, and connected by roads."
The sites are spread over about 60 miles between the Kuban river in the west and the city of Nalchik in the east.
The decorations and forms of bronze items found in the area indicate the civilization is linked to the Kuban civilization, which was discovered at the end of the 19th century at the foot of Mount Kazbek and is known for its artistic bronze works.
The discovery of this older civilization "was possible thanks especially to old black-and-white photographs taken in the Soviet Union," said Dmitry Korobov, another participant in the expedition.
Using modern research methods such as global positioning systems, the archeologists were able to use the photographs to uncover the sites, which are at a height of between 4,620 feet and 7,920 feet.
Valentina Kozenkova, an archeologist specializing in the Caucasus at the Russian Academy of Sciences, said the discovery was of historical importance.
"This is a discovery without parallel, notably for the number of sites found in the same place," she said.
"The impact of this work is even more important because these 200 sites are in very good condition thanks to their location," she said.