The Kemenuh Butterfly is a little magical place to explore. It is really close to the Tegenungan Waterfall so perhaps combine them together. Both are only 15 minutes from Komune Resort in Keramas. From memory it is under 100 000 rupiah( my Dad paid so I am not 100%) and you get an interesting orange drink on arrival. You can wander for as long as you wish through the beautiful garden as the butterflies float about and you can learn about their lifecycle which is everso brief and fleeting. There is a restaurant there also if your feeling peckish and you can have one of those random experiences of having giant butterflies placed all over you by the gorgeous young guide, an experience I didn’t know I wanted until it happened.