Ride the Fansipan cable car. The 15-minute ride from Sun World Fansipan Legend station crosses the whole Muong Hoa valley before climbing to 3,000 m; a short funicular and stairs finish the trip to the 3,143 m summit gates. Return tickets cost around ₫800,000 ($30). On a clear day this is the single best thing in Sapa. Mornings have the best visibility.
Trek the Muong Hoa valley. The classic day route runs from Sapa town through Lao Chai and Ta Van villages — about 10-12 km of ridgeline paths through the terraces with lunch in a village home. It is moderate walking, fine for anyone who can handle stairs for a few hours.
Walk to Cat Cat village if you want an easy taste instead. It is under 3 km from town, with a waterfall, water wheels and craft stalls. It is the most touristy village, so treat it as a stroll, not a cultural deep-dive.
See the town itself — the stone church, the lake and the food street where you can try grilled skewers and hotpot on cold evenings. The weekend market brings hill-tribe traders into town with textiles and silver.