Cave National ParkCentral Kentucky, USA. The longest known cave system in the world.
Marble Caves at General Carrera Lake in Patagonia (Argentina and Chile).
The Baatara gorge waterfall (also known as the “Cave of the Three Bridges”) in Tannourine, Lebanon. The waterfall drops 255 metres (837 ft) into the Baatara Pothole, a cave of Jurassic limestone located on the Lebanon Mountain Trail.
These could have been a source of water/safety for people in the aftermath of the nuclear war
Aquamarine (floater). Jacqueto Mine, Minas Gerais, Brazil - Cool Nature
Lovely cluster of gemmy blue Aquamarine crystals with accenting Muscovite blades on Albite!Pakistan95mm.
Horse Mountain Iris Agate - now this is truly a mini rainbow to keep!
Opalo de Fuego