750 ft Underground: Carlsbad Cavern - The Big Room (New Mexico)
This is a combination of long exposures in the dimly lit interior of the vast Big Room inside Carlsbad Caverns in Southern New Mexico. It is located 750 feet underground in the Guadalupe Mountains. This room is mostly limestone, 4,000 feet long, 625 feet wide, and 255 feet high at its peak. I believe it is the seventh largest cave chamber in the world. 6.2 football fields would fit comfortably down in the Big Room.