In the 19th century, the Lao Cai area served as fighting ground for various armed groups, among which the famous Black Pavilions and White Pavilions. These gangs of plunderers had taken refuge in the mountains of Vietnam after the Taiping rebellion in China. Their main purpose was to control the shipping trade on the Red River. Sea salt from Vietnam, opium from the Yunnan province, new rice, fabrics, manufactured goods were to be their primary objectives. Between 1850 and 1886, the town of Lao Cai was taken, destroyed and fortified several times by different groups.
Today, there is a very good road from Lao Cai to Sapa, it is 38 km. Everyday, there are lots of tourist buses and taxi to transfer tourists from Lao Cai to Sapa and return. It costs around 2 USD for a sharing tourist bus ticket and 18 USD for a private taxi or van.
There are some villages near to Sapa where you can do a homestay.
If you have 2, 3 days in Sapa and have a tour guide, the first day you will have a long trek for about 5 or 6 hours along small village trails. Here is some advice and information for your trip.