Photos: Trantuanviet, Wikimedia Commons (CC BY-SA 4.0); Dave Bunnell, Wikimedia Commons (CC BY-SA 4.0); Linhcandng (thảo luận), Wikimedia Commons (CC BY-SA 3.0)
Landmark, Vietnam
Son Doong Cave
the largest cave in the world, with its own forest and clouds inside, guided tours only
Bố Trạch, Quảng Bình, Vietnam