Halong Bay is an enchanting place where ancient, mountainous rocks rise up from the sea. The water is calm and warm, even in the winter and it's a beautiful emerald green. I was skeptical about taking a tour at first, but that's probably the best way to get the most for your money here in Vietnam. I saw Halong Bay on a "Junk" - easily booked a two day/one night stay through the hostel I was staying at. It was a fantastic experience - going during the winter is hit or miss - I got lucky and it was a beautiful, clear day. The boat cruise was an experience in and of itself; the food was fantastic and the room was comfortable - the gentle rocking of the boat lulled us all to sleep. In addition to looking at the amazing scenery, we also got off the boat and climbed up to visit a massive cave, then later went kayaking around the mountains.