Onward to Laos
Many make Chiang Rai or Chiang Saen their last port of call in Thailand and head overland to rugged but inviting Laos. It is possible to travel downriver 70km (43 miles) to Chiang Khong, a small border town (buses and local songtaews also make the connection from either Chiang Rai or Chiang Saen). You'll need to arrange a visa to enter Laos, which is best done in Bangkok or Chiang Mai at any travel agency. Once you're over the border, the slow boat to Luang Prabang is rugged but memorable.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.