A descent of the River Nam Song is the highlight of a stay in Vang Vieng. On a tubing excursion, visitors are transported by the current on large lorry inner tubes, while kayakers can enjoy a less frenetic experience as they negotiate short rapids between two sections of calmer water. The stretches of river covered, ranging from 4km to 20km for the most adventurous, pass through stunning landscapes in the shadow of karst mountain ranges.