Kanchanaburi's The Rice Barge Restaurant at Dheva Mantra (034-615-999, www.dhevamantra.com) floats on the River Kwai and serves up local specialties like pla khang (red tail catfish), with prices ranging from B280-B320.
 
It's long been one of the nicest places near the city to have a riverside tete-a-tete with a bit of fine-dining polish. And it's just been refurbished to even grander, Rama V-era luxe, complete with air-con and a Thai-style deck to eat on while collapsed onto a triangular pillow. Not quite as charming, perhaps, but a whole lot comfier and it'll stay open during monsoon downpours. 
 
Open for dinner only (6-11pm). Rooms at the equally swanky Dheva Mantra start from B3,700 a night for superior and B4,400 a night for riverside view deluxe room.