Carlsbad Caverns, Carlsbad New Mexico

The cavern development began about 250 million years ago when a reef formed along the edge of an inland sea. the sea eventually evaporated and left the reef buried under deposits of gypsum and salts. Then, 20 to 30 million years ago, the Guadalupe Mountains were uplifted thousands of feet above sea level, fracturing the ancient reef. ya da ya da ya da......Anyway, it was absolutely breathtaking to see what many call the Eighth Wonder of the World. Our walk down from the outside entrance, about a 750 foot descent, was strenous. The path is steep, with numerous switchbacks. I must have been crazy to consent to doing it, but it was something we would have truly regretted not doing. We also had a private rangers guide to view a place called Kings Palace where some movies have even been filmed. No more of that though with all the preservation rules today. It is an absolute "must see"!