Wat Roka Kandal is the most interesting of Kratie's several Buddhist temples, notable for its age — parts of the structure date to the 19th century — and for its position on the riverbank just south of the main town. The original vihara (main prayer hall) has some original murals that survived the Khmer Rouge period, when most temples in Cambodia were damaged or destroyed. The monks here are approachable and the temple has a peaceful, unhurried atmosphere.
The approach along the river road is pleasant in the morning, with fishing boats coming in and locals setting up market stalls. The temple is not a major tourist sight, which is part of its appeal — you're unlikely to encounter tour groups, and the monks often welcome conversation. A small donation box is near the entrance; drop in what you think is appropriate.