We took the train from Bangkok to Chiang Mai expecting that seeing the countryside would be better than flying.   In fact there wasn't much to see and it was a long, rough, and dirty ride.   The bathroom fed straight onto the tracks, and since it was the type requiring people to squat, the floor around it was often wet.   It was impossible not to track wet nastiness back down the aisle to the seat.   Someone mopped the aisle several times during the journey, but as far as I could tell continued to use the same bucket of water.   By the time we arrived in Chiang Mai Deborah had dark dots on her feet from the black soot coming through the holes in her Crocs, and we were grossed out by the blackness of what eventually came out of our noses.   I recommend flying, which is what we did on the return journey.   The river cruise was peaceful, downtown Chiang Mai is lively and interesting, and the Elephant Nature Park is worth the trip (separate gallery).