If you are ever in Sinharaja and you see a small body of water, even something that would be deemed a pond with exaggeration of the highest order, do tread softly. You could be inches from one of Sri Lanka’s most beautiful, endemic snakes, the Green Pit Viper (Trimeresurus trigonocephalus). And you don't want to scare it away.
Emerald green, yellow and burnished black would probably be an adequate description for this little jewel of a snake. I had never seen one until a trip to Sinharaja in February with the Adventure Lanka crew where we saw around three of them near small bodies of water, the snakes entwined in the undergrowth.
Of course these snakes are poisonous, though fatalities apparently have never been recorded, so treat the snake with the outmost respect and you will get some great macro photographs.