Koh Trong is a large island in the Mekong directly across from Kratie town, accessible by small ferry in a few minutes. Once across, the island is entirely different in character from the mainland — it's agricultural, quiet, and almost completely car-free. The main circuit around the island can be cycled comfortably in a couple of hours, passing pomelo and fruit orchards, Cham Muslim fishing villages, and a small Vietnamese community that has lived on a floating village on the island's eastern shore for generations.
The island is particularly good at dusk, when the light on the river turns orange and the temple bells from Kratie carry across the water. You can hire bicycles on the island after arriving by ferry, and a few simple homestays operate there for those who want to stay overnight. The ferry crosses frequently and costs a few hundred riel.