Trekking & Hiking -- Hiking in Sapa's picturesque landscape and among Vietnam's traditional ethnic minorities is one of the main reasons visitors flock to this northern region. Convenient to the town center, the Lao Cai-to-Ta Van day trip from Sapa is a chance to traipse around the rice terraces and experience a bit of rural village life. Unfortunately, the convenience also means there are many tourists around. Visitors are often assaulted by (mostly Hmong) villagers trying to sell their handicrafts and wares, and many do not accept "no" for an answer. This is a tour to do only if you are pressed for time. Hire a car or motorbike for the 9km (5 1/2-mile) road down the valley from Sapa to the Hmong village of Lao Cai (some folks even walk it); it's a nice ride in itself, with great views of the lush terraces. From there, just follow the valley for a few miles to the next town of Ta Van. Along the way, you'll walk through terraced rice fields and among some picturesque villages, and experience a bit of rural life. (Entrance fee is 5,000 VND. Drop-off at Lao Cai and later pickup at Ta Van is about $4 with a motorbike taxi and $25 for a jeep.)
As you walk through different hilltribe villages (Hmong and Dao people), it's helpful to have a guide to explain customs or practices to you and perhaps translate. Farther afield, I found hikes 2 to 3 hours north of Sapa, among the Tay villages, to be less traveled; the Tay people were more shy and respectful of passersby (that is, no trinket sellers following you mercifully for hours on end). You'll still be greeted with a hearty "Hello! Allo!" wherever you go.
Ask at your hotel front desk, or contact Topas Adventure Travel for longer, less touristy treks. It is, in fact, illegal to hike without a guide, and you may find yourself a very unwelcome visitor in a village that does not accept tourists. Besides, local guides are knowledgeable about levels of difficulty and which hikes are more secluded and less touristy.