Sa Pa trekking tours are sold as packages from Hanoi rather than as day trips, because the journey is too long for anything else. Sa Pa sits in the far northern mountains under Fansipan, which at 3,143 metres is the highest point in Vietnam. The valleys below are terraced for rice by Hmong, Dao, Tay and Giay communities, and they look completely different between planting and harvest. Expect cool air and mist that lifts late. The standard shape is 4 days and 3 nights, priced per person by hotel class on a three, four or five-star tier. The Fansipan Summit package includes all three nights, breakfast every day, lunch on the trekking day, private car transfers at both ends and every entrance ticket on the itinerary. The Topas Ecolodge version puts you at 1,400 m above the valley and includes private van transfers Hanoi to Lao Cai to Sa Pa and back, plus guided trekking through the Muong Hoa Valley. Both handle the overnight leg, which is the part that goes wrong when people book it piecemeal. The choice underneath all of this is cable car against trek. The Fansipan cable car takes about 20 minutes and suits families or a short stay; a guided 2-day trek to the summit is a serious walk that needs the fitness to match. Both reach the same peak, and only one leaves you a day to spare afterwards. For the valleys, take a guide from the Hmong or Dao communities: the paths are not obvious once you leave the main route, and the weather turns faster than visitors expect. Plan 2 nights in Sa Pa at the very least, never one.