One of the closest temples to the river is Wat Long Khoun. You can take a boat from the landing in front of Wat Xieng Thong directly across the river to the temple.
Wat Long Khoun, with its tiny sim, was in fact a very important place in the old royal days. It was the custom for the kings of Luang Prabang to come to the temple for a retreat just before their coronation.
The small sim is fronted by an unusually large veranda, which probably served as a sala. The single entrance to the sim is guarded by murals depicting two large Chinese warriors.
Around the compound are several large elevated monk's cells (kuti). The brick and plaster stairways leading up to the upper level are moss-encrusted, giving the place an air of stately decay, even though it was extensively restored in 1995.
Near Wat Long Khoun is a cave temple, Wat Tham Xieng Maen, which nowadays stores old and damaged Buddha images. It is generally only open during the Lao New Year.