A group of Japanese filmmakers arrived in the central Quang Binh Province on Sunday to shoot a 3D documentary about Son Doong, the world's largest cave in the province.
A member of the 12-strong film crew of Kyodo news agency said it will be the first 3D film about caves in the world.
The documentary will focus on the lives of creatures in the massive cave and the surrounding forests.
Experts from the British Cave Research Association, who discovered the cave in 2009, will accompany the filmmakers.
A local man, Ho Khanh, was considered the first person to actually find the cave in 1991 but then forgot the entrance. Khanh will now be the guide for the film crew.
The film will finish shooting on May 23. It is expected to be broadcast late this year in more than 160 countries and territories.
In 2009, a caver team of the British Cave Research Association discovered the Son Doong Cave at the UNESCO-recognized world heritage site Phong Nha-Ke Bang National Park near the Laos-Vietnam border.
The cave measured at 200 meters high and 150 meters wide at its largest, nearly double the previous world's largest cave - the Deer Cave in Malaysia - which is 100 meters high and 90 meters wide.
The expedition also found En Cave, located above the Son Doong Cave, measuring 150 meters high and 130 meters wide.