Halong Bay & Bai Tu Long Bay
The UNESCO World Heritage Site of Halong Bay actually includes three bays: Halong, Bai Tu Long and Lan Ha, and this area is one of Vietnam's most iconic sites. All of the bays feature incredible limestone karst scenery, with thousands of islands of varying shapes and sizes. The best way to explore one of the bays is by boat, with many options for overnight cruises available.
Halong Bay is justifiably regarded as one of the world's seven natural wonders. As well as the dramatic island scenery there are other-worldly caves, hidden coves and floating villages. Exactly what you see will depend on which bay you visit, but all boast a treasure-trove of exciting activities and natural beauty.
Halong Bay is the most popular, with the largest number of cruise options, and around 2,000 islands. Bai Tu Long Bay is quieter, with much fewer boats, although it still has around 1,600 islands. Lan Ha Bay, which is also known as the Cat Ba Archipelago, has much fewer islands (around 300), but this is the location of Cat Ba Island, which is the largest island in the area. Lan Ha is more remote and therefore quieter, with much fewer tourists, but this does mean there are fewer boats to choose from should you wish to cruise.
Cat Ba Island has some pretty beaches, and there are also plenty of adventurous activities such as trekking, cycling and rock climbing.