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.
By pure chance and blind luck, this man had discovered an entrance that had remained hidden from man for millions of years into what would turn out to be the largest cave in the world, a behemoth five times larger than the largest known cave at the time. Worldâs largest cave. For years the entrance remained unexplored.