This is the 12397th most frequent Russian word.
карьеров
"Карьеров" is the genitive plural form of "карьер," which means "quarries" or "careers" (depending on context).
In this sentence, 'карьеров' refers to quarries or places for extracting minerals or resources from the earth.
Вокруг города расположены несколько больших карьеров.
There are several large quarries around the city.
Here, 'карьеров' is used to indicate old quarries that are commonly used for leisure activities like swimming.
Мы часто ездим к старым карьерам, чтобы купаться летом.
We often go to old quarries to swim during the summer.
In this sentence, 'карьеров' pertains to quarries in the context of environmental studies.