The best day-trip from Louang Phabang is the picturesque, multi-level Kouang Si waterfall, tumbling 60m before spilling through a series of crystal-blue pools. Vendors near the lower pool sell tam màk hung, fruit and drinks. The steep path on the opposite side of the falls leads to a grassy meadow filled with brilliantly coloured butterflies. The path can get quite slippery, so be very careful.