Many caves in Europe contain remains of those generations of bears living there. Several are even called Bears' Cave, due to the remains found there.
Very often those remains were used to produce fertilizer or gun powder. Both didn't work very well or at least not for very long. Even meters of deposits are soon at an end, if they are carried away with heavy machinery.
This is a list of caves that share this kind of history. Most of them are famous for their cave bear remains, some contained the bones of hundreds or thousands of bears. Some of them are important steps in the scientic explorations of cave bears. All those caves and other finding places of cave bear remains tell us, in which area cave bears lived.
The grey area on the map shows this. Its ends to the east a little bit outside the map, at the Aral lake.