VietNamNet Bridge - Swiss photographer Urs Zihlmann captured the amazing images of Son Doong, the world’s largest cave, during a five-day trip to the Phong Nha-Ke Bang national park in the central province of Quang Binh, Vietnam.

At more than 200m high, 150m wide and 5km (3.1m) long, the Hang Son Doong cave in the Phong Nha Ke Bang National Park is so enormous it has its own river, jungle and climate.

Even clouds form inside the beautiful echoing tavern, which is tall enough to fit a 40-storey skyscraper.

Adventurers must complete a tough half-day trek through jungle and across deep rivers to make it to the entrance, even passing through the third largest cave in the world to reach their final destination.