I have been using swimming pool wherever I have stayed in Sri Lanka. Each hotel had a big pool- anywhere from 35 meter to 50 meter in length. Most of them were facing the ocean. They are nice, long and clean. Some of them had fantastic little lights under and it was awesome to swim in the dark over them. Loved the experience all around.
My favourite pool so far has been in Kingsbury hotel in Colombo and the least favourite one was in Anilana in Trincomalee.