Thien Ha cave is part of the 200-metre-high Tuong Mountain (Mount General), a defensive fence protecting the ancient capital of Hoa Lu from foreign invaders in the 10th century (Photo: VNA) 
The entire cave is around 900 metres deep, but only 700 of which are accessible by foot (Photo: VNA) 
Majestic beauty of Thien Ha cave (Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) 
(Photo: VNA) VNA
