If you've got some time before or after taking a bath (if you're staying the night, for instance), you might like to sample the butterfly farm above the baths, with lots of flowers and several species of butterflies, including the Raja Brooke's birdwing.
First you see displays of the butterflies and other insects mounted under glass, then you enter the butterfly enclosure. Take your time in the enclosure as new butterflies constantly materialise before your eyes.