$\text{The seascape of Ha Long Bay is one of the UNESCO World Heritage Sites. With views best seen by boat, this is top tourist territory. You should choose at least one overnight tour to see the sights of Ha Long Bay because a day trip is not suitable for that. There are many caves in the bay that can be accessed including Sung Sot Cave, with three mammoth caves, and Dao Go Cave, with beautiful stalagmites and stalactites. The highlight, however, is simply immersing yourself in the changing scenery of the spires as you pass by.}$