Carlsbad Caverns in New Mexico with stalactites, stalagmites, and an incredible variety of other formations began over 500,000 years ago. It happened slowly, drip by drip.
In the late 1800's. Young 16 year old cowboy, Jim White, discovered the main cave when he noticed thousands of bats rising up out of the ground at dusk. He entered the natural entrance on a rope with a lantern and the rest is history. Early on the cave was mined for guano (bat poop) as a natural fertilizer.
In 1923 Carlsbad caverns was proclaimed a national monument. In 1930 it became a national park.
After a 1995 National Geographic article the site was designated a World Heritage site with over 100 other caves spanning 146,766 acres.
Cave scientists and experienced cave explorers have received permission to explore these other caves and their ecosystems. They are not open to the public.