As you could probably guess from the previous pictures, I toured Carlsbad Caverns National Park today.
The natural entrance is totally the definitive way to enter the caves, but they're not kidding when they say it's long and steep - about an hour to descend the 750 feet vs. about a minute in the elevator. The Big Room is a one-and-a-half-hour self-guided tour of the (obviously) big room. I also did the King's Palace ranger-guided tour, which was solid but had too many people for me to feel comfortable taking a ton of photographs. The part where they turned off the lights was worth it, though.
Back again tomorrow for the Slaughter Canyon Cave tour for obvious reasons (the ones where you crawl through stuff were sold out). But it's small, involves ladder climbing and flashlights, and has a creepy name. I'll let you know if I survive.