Son La’s welcoming, low-key charm is enhanced by its valley-edge setting, and it merits more than the usual overnight stop. If time allows, there’s enough of interest to occupy a few days, taking in the old French prison and a nearby cave, as well as making forays to nearby minority villages on foot or by motorbike.

Certain minority villages stage events for tour groups, such as traditional Thai dancing or supping the local home brew, a sweet wine made of glutinous rice; it’s drunk from a communal earthenware container using bamboo straws, and hence named ruou can, or stem alcohol. The major part of Son La lies off the highway, straggling for little more than a kilometre along the west bank of the Nam La River.

The French prison

Son La’s principal tourist sight is the French prison, which occupies a wooded promontory above To Hieu and offers good views over town. The two turn-offs from the highway are both marked with chunky stylized signs suggesting incarceration; walk uphill to find the prison gates and an arched entrance, still announcing “Pénitencier”, leading into the main compound. This region was a hotbed of anti-French resistance, and a list of political prisoners interred here reads like a roll call of famous revolutionaries – among them Le Duan and Truong Chinh, veteran Party members who both went on to become general secretary. Local hero To Hieu was also imprisoned for seditionary crimes but he died from malaria while in captivity in 1944. Most of the buildings lie in ruins, destroyed by a French bombing raid in 1952, but a few have been reconstructed, including the two-storey kitchen block (bep), beneath which are seven punishment cells. Political prisoners were often incarcerated in brutal conditions: the two larger cells (then windowless) held up to five people shackled by the ankles. Behind the kitchens, don’t miss the well-presented collection of prison memorabilia. Enter the second arched gate and upstairs in the building on your right you’ll find an informative display about the dozen or so minorities who inhabit the area, including costumes, handicrafts, jewellery and photos.

Que Lam Ngu Che Cave

The cave most convenient to Son La is Que Lam Ngu Che Cave, which is situated just north of the town centre and has a small shrine inside surrounded by strange formations in the rock. A five hundred-year-old poem written by King Le Thai Tong carved into the stone remains visible today on the outside of the cave. You can go there alone – just look for the sign 150m as you head north out of town, or a guide from the Trade Union Hotel will take you for a small fee.

Ban Mong

An interesting destination for a day’s trek or visit by motorbike is BAN MONG, a Black Thai village six scenic kilometres along a luxuriant valley south of Son La. The houses of this village are solid, wooden structures surrounded by gardens of fruit trees rather than vegetables. The women of the village usually wear their hair piled up high on their head and secured with a head-dress, on top of which they often wear a precariously-perched crash helmet. The dress of the Black Thai women is particularly striking – especially the brightly embroidered headscarves that they drape over their long hair piled up in huge buns. Their tight-fitting blouses with rows of silver buttons, often in the shape of butterflies, are also distinctive. In colder weather, many wear a green, sleeveless sweater over the blouse, or a modern jacket in pink, blue, green or maroon.