view of prohodna cave also known as god`s eyes near karlukovo village, bulgaria. colorful cave formation with giant entr

adventure also amazing ancient background balkans beautiful big bulgaria cave colorful destination ecology ecotourism entr entrance europe eyes famous formation geologic geology giant god gods hole inside karlukovo known landscape mountain mysterious mystery mystic natural nature ochi panorama panoramic phenomenon prohodna rock stalactite stalagmite stones tourism tourist travel underground view village wall