Braidwood is a city in Will County, Illinois, United States, approximately 53 miles (85 km) southwest of Chicago and 18 miles (29 km) south of Joliet. The population was 5,203 at the 2000 census. The Braidwood Nuclear Generating Station, a nuclear power plant currently owned by Exelon Corporation, is also located in the area (although the plant's address is actually in the nearby town of Braceville).
The Son Doong Cave in Vietnam is the biggest cave in the world. It's over 5.5 miles long, has a jungle and river, and could fit a 40-story skyscraper within its walls. But nobody knew any of that until about six years ago.
6. Carlsbad Cavern, New Mexico, United States â The caves are the main attraction of a national park called Carlsbad Caverns National Park. They include the Big Room, a natural limestone cave chamber which measures 1,219 by 190 meters (4,000 by 625 feet), and 107 meters (350 feet) high at the highest point.. Mammoth Cave, Kentucky, United States â Located in the Mammoth Cave National Park, the Mammoth cave is the longest cave system known in the world. The cave system is remarkably stable and is known to include more than 390 miles (630 km) of passageway. Mammoth Cave, Kentucky, United States.