Hozugawa river boat ride
https://gyazo.com/1dafe2b3b0908204baaebdd905457e41
N35.0144954,E135.5857114,Z14 Hozugawa+River+Boat+Ride+(Hozugawa+Kudari)
Following roughly the same path of the Sagano scenic train you can take a boat ride through the Oi (hozu) river valley.
It's particularly nice in the fall when all the Maple leaves turn into their many colors.
You can start from kameoka or Katsura
West