In Battambang, Cambodia, we did a day trip in the countryside on the backs of motorcycles, ending our trip at the norry, a makeshift bamboo train that runs on the Cambodia Railway tracks. Cambodia has no good train system, but has a series of leftover tracks from when the trains used to run. So, people in villages started building makeshift trains to run on the tracks that could be quickly disassembled when a real train came (very slowly) in the opposite direction. They aren't used as much today now that motorbikes are everywhere in the countryside, but you can still pay to hitch a ride at break-neck speed on one of the trains.
It was a cross between a toy train and a rollercoaster, and we sped along for half an hour, then turned around and sped back. We didn't meet another train, but clattering and bouncing down the old tracks was so much fun.