Honestly speaking, I know next to nothing about Sera Falls, except that there's a cave behind it and that it looks nothing short of fantastic during the rainy season when it's in full bloom.
It's about a fifteen to twenty minute's drive from Riverstone and Mini World's End — drive straight down from Mini World's End and take a couple of left turns. Better yet, ask for directions from the ticketing officers at Mini World's End.
Reaching the falls requires climbing down some stairs and passing a rock wall coated in guano.
But the sight, the pool itself, is stunning. Great for photo ops, but do keep in mind that like nearly all other waterfall pools this is also incredibly deep — so don't try wading across unless you can really swim. The friend I was with swam a couple of laps to see if he could help me get across and then firmly said it was too dangerous.
It's like a little haven though, set firmly in between walls of rock and trees on three sides. The pool continues into a river-like waterway through a lot more rocks.
There are hundreds of little fish, bugs, and swarms of colourful dragonflies all over the place. It's not hard to imagine you're one of the kids in a Jurassic Park movie, and to keep an eye out for a sudden dinosaur to make its way through the foliage.
The waterfall was pretty thin when we went — because there hadn't been much rain; but that whole wall of rock is basically covered in a massive curtain of water when it's the wet season. Btw, notice the shadowy patch and the random plant in the middle-right of this photo? That's a cave; there are steps leading up to it, and it's basically behind the waterfall and quite easily accessible.
It's a nice fall. Gets quite crowded though, but people don't hang around for too long. We were there for a couple of hours and about four groups came and went within that time. Worth checking out if you want to explore and fall-hop, but not accessible unless you have private modes of transport.