2 Best Sights in Halong Bay and North-Central Vietnam, Vietnam

One of the most intriguing sights on Cat Ba Island, Hospital Cave served as a bomb-proof medical facility during the American War. It also provided well-hidden refuge for Vietcong leaders and fighters during the conflict. Like Cu Chi Tunnels in the south and Vinh Moc Tunnels near Dong Ha, Hospital Cave is a prime example of the Communists' engineering ingenuity. Built between 1963 and 1965, the three-story facility is a labyrinth of dim chambers. Guides operate from outside the cave, which is around 10 km (6 miles) north of Cat Ba Town and will show you around the 17 rooms and point out notable features such as the old operating theater and a natural cavern that was used as a movie theater.

While the cave itself is not that impressive, the views from the top of the mountain are breathtaking, featuring Tam Coc River on one side and rice paddies on the other. The climb and its 486 steps are steep but worth it. There are several parking lots outside the entrance where you will be charged 10,000d for a bicycle and 20,000d for a motorbike. The views are the best on a clear day and comfortable footwear is suggested. If you are visiting for only a short time, skipping the cave is advised.