Nestled deep in the jungles of Phong Nha Ke-Bang National Park, the magazine states that Son Doong Cave is the world’s largest of its kind, featuring the planet’s largest chamber measuring 600-feet high, 300-feet wide, and over 2.5-miles long. Each year, only a handful of tourists are permitted to enter, with groups going into the cave as part of a five day expedition that involves two nights of camping inside of Son Doong Cave. Most recently shots of the famous cave appeared in the Christmas Day promotional teaser for DJ Alan Walker’s latest MV "Alone Pt. II", with images of Son Doong Cave appearing alongside other beautiful snaps of central Quang Binh province./.