A highlight of the long trip East was Viengxay, the headquarters of the Pathet Lao Liberation Army during the war with the US. A large area of kaast hills, cliffs and particularly caves hid an administration centre protecting up to 20.000 people. They hid in the caves by day and emerged by night to cook and tend crops, constantly being attacked by US war planes. The caves were strengthened with concrete blast deflectors and key installations had gas proof bunkers. Other caves functioned as hospitals, theatres, storage and living quarters. The red prince Souphannouvong who sided with the communist Pathet Lao lived there and created a beautiful garden, even converting a bomb crater into a heart shaped lilly pond.