Oudomxay:The town of Muang La is home to the important Saymoung Rattana Stupa which houses a 400-year-old Buddha image. Adventurers will want to explore Chom Ong Cave, it is the longest and largest known cave in Laos at around 18.4km long. Flights run three times weekly from Vientiane to MuangXay on Tuesdays, Thursdays and Saturdays. Adult prices start from 399,000 kip one-way.