Designated a World Heritage site in 1994, Halong Bay is undoubtedly beautiful. There are just shy of 2,000 limestone islets in the bay, and it is probably on most people’s agenda when they visit Vietnam. March seems to be foggy a lot of the time unfortunately, but visibility seems to improve after a bit of rain. The weather is quite changeable, so even if it’s foggy and hazy in the morning does not mean it won’t clear later on in the day, even if it’s only for a couple of hours. Boat cruise aside, you can explore caves, kayak, swim, get on Cat Ba Island for a bike ride, and more. Yes, it’s touristy, and it’s popular, but clearly for a reason.