Ramboda Falls isn't hidden — it's right off the main A5 between Kandy and Nuwara Eliya, which is exactly why I almost didn't stop.
I'm glad I did. 109 metres of water dropping in two clean stages, close enough to the road that you can hear it before you see it.
There's a small viewing platform a short walk down from the roadside, plus a set of steps if you want a closer (and wetter) look.
Best light is mid-morning, before the tour vans start stacking up in the layby. Bring a jacket you don't mind getting misted on.