Erawan Falls, not far from Kanchanaburi, is a 7 tiered, cascading turquoise blue water fall that is surrounded by dense forest. Named after Erawan, the three-headed white elephant of Hindu mythology, the falls is located in the 342 sq mile Erawan National Park.
You can walk to the top level and back in about 2 hours, it is a fair trek which is slippery and tricky in sections, but its well worth it if your up to it. Reward yourself with a swim in one of the beautifully blue pools on the way back down. Be ready to be tickled as the harmless fish that live in the pools nibble at the skin on you feet, this makes for a slightly less relaxing swim but an amusing experience as shreaks and laughter rings out all around.
Most organised tours from Kanchanaburi include a stop at the Erawan Falls, I’d say the 3 hours ours had was about right, if you want to explore the National Park trials you could always make your own way there by Songthaew or bus. The falls are incredibly picturesque so set a slow shutter speed and get snapping!