Hang Tien, also known as Fairy Cave, is part of the Tu Lan Cave system, located in the Cao Quang commune in the Tuyen Hoa district north of Phong Nha. It was first explored by British cave experts in 2010, and tours began to this spectacular cave in 2016. The Cave system was believed to have been formed around 500 million years ago, and until (geologically) recently, was filled with water. It is an incredibly vast cave, with a total length of nearly 3km when both branches of the cave system – Fairy Cave 1 and Fairy Cave 2 – are taken into account. The opening of the cave is 50 metres wide, and 70 metres high. It is famed for its large formations, and has become a very popular cave with photographers. It can be seen on either 1 day, 2 day or 3 day tours.