Ramboda Falls is high and highest waterfall in Sri Lanka and highest waterfall in the world. It is situated in Pussellawa area, on the highway at Ramboda Pass. It formed by Panna Oya which is a tributary of Kothmale Oya.
Peradeniya Botanical Garden in Sri Lanka - beautiful surroundings to the University of Peradeniya, which I also want to visit. Situated in the centre of the island, so will need to combine with a visit to Kandy.