The things worth doing in 4000 Islands (Si Phan Don), from the obvious landmarks to the ones locals actually rate.
Kayak the Mekong channels
Half-day guided paddles between islands and past the rapids. Wear the life jacket; the Mekong here has strong, sudden currents.
Swim off a Don Det beach
Sandy river beaches appear as the water drops. Dry season only, sober only, and only where your guesthouse says it is safe.
Wat Khon Tai
A quiet working temple on Don Khon among old trees and Khmer-era stones. Cover shoulders and knees and leave a small offering.
Watch the fishermen at Li Phi
Bamboo traps and platforms rigged into the rapids, a fishery worked the same way for generations. Watch from the marked walkways.
Do absolutely nothing
The islands' real attraction: a hammock, a book and the Mekong sliding past. Most people book two nights and stay four.