Goa doong Son in Vietnam has a length of about 5 km, height 200 m, and width of 150 meters which was named the world's largest cave beat Deer Cave in Malaysia which is only 2km in size, height of 100 meters, and width of 90 meters. Goa doong Son National Park located in Phong Nha-Ke Bang, Bo Trach District, Quang Binh Province, Vietnam is in addition to having a very large size also has another uniqueness of this cave could spend all day whistling sound no matter how it's night or day.
British researchers came to this cave in the last year and began to make observations and surprised by the size of this cave, British researchers also investigated the strange noises like whistling issued by this cave. And a team of British researchers from the British Cave Research Association, the work reveals the strange noises that had been feared by the population. According to them the strange whistling wind also comes from an underground river where the water is very swift, so strange noises echoing it.