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 park encompasses incredible caves and karst formations in a mountainous equatorial rainforest setting. The Sarawak chamber found in one of the underground caves measures 700 by 396 meters (2,300 feet by, 1,300 feet) and at least 70 meters (230 feet) high and is the largest cave chamber in the world.