- Top 11 Caves
- Mulu Caves in Borneo features world's largest cave chamber, 1.66 million square feet
- Clearwater Cave System spans 30 miles in Southeast Asia
- Lechuguilla Cave in New Mexico is 150 miles long and 489 meters deep
- Wind Cave in South Dakota is densest cave system with 154 miles of passages
- Shuanghedong Cave Network in China spans 150 miles with underground ecosystems
- Optymistychna Cave in Ukraine is world's longest gypsum cave, 161 miles long
- Sistema Ox Bel Ha in Mexico spans 167 miles, formed 18,000 years ago
- Jewel Cave in South Dakota features colorful crystals on inner corners
- Sistema Dos Ojos in Mexico spans 200 miles, connected to underwater system
- Mammoth Cave in Kentucky spans at least 365 miles, discovered 4,000 years ago
- Son Doong in Vietnam is world's biggest cave, 1.35 billion cubic feet
- Historical Context
- Ancient humans painted on cave walls over 40,000 years ago
- Neanderthals may have painted on Iberian Peninsula caves 64,000 years ago
- Many caves contain animal figures from over 40,000 years ago