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.
The aptly named Mammoth Cave is the world's longest-known cave system with over 285 miles of surveyed cave passageways. If you like the spelunking, this is the place for you. Visitors can explore the vast chambers and complex labyrinths, sometimes climbing up hundreds of stairs and steep hills.