Chevé Cave
Chevé Cave ( ; ) is a deep cave located in the Sierra Juárez mountain range in the southern Mexico state of Oaxaca. As of 2003, its deepest point has been measured at deep, making it the second deepest known cavern in the Western Hemisphere and the world’s 12th deepest cave. The cave's deepest known point is nearly one vertical mile and seven horizontal miles from the entrance, ending in a terminal sump. The present limit of exploration in Chevé, at 9.3 kilometers from the nearest entrance, represents one of the most remote locations ever attained inside any cave on Earth. The logistics of reaching this point are enormous: more than two kilometers of rope need to be rigged and three underground camps established. Chevé is the deepest proven freshwater hydrological system in the world. Temperatures in Chevé are moderate, ranging from . It has been most thoroughly explored under the leadership of caver Bill Stone.
Wyandotte Caves
The main entrance to Wyandotte Cave is 220 feet (67 m) above the level of the Blue River. Wyandotte Cave is known for its long open passageways and large rooms. With 9.2 miles (14.806 km) of passageways on five levels it is the fifth longest cave in Indiana. Included in its formations is Monument Mountain. At 135 feet (41.148 m) tall, Monument Mountain is considered to be the world's largest underground mountain. Wyandotte Cave is also home to a great many helictites, which are considered rare. The cave is also home to the tallest stalagmite in the world, known as the Pillar of the Constitution, but this is only visible on crawling tours.