Jason A.
Yelp
Who are these idiots rating the Butterfly Garden at Changi Airport a 4 star because the butterflies are sleeping? Oh yeah, Martin B. on 11/13/2014. Ignore him.
This is a phenomenal place inside of an airport, that would actually be worthy of a paid admission if it happened to be elsewhere. It's 100% free, and you have the opportunity to see hundreds of butterflies in this incredible environment, with a backdrop of airplanes taking off. Prepare for a little humidity, and not enough room to maneuver your luggage around. I suggest you leave your bags outside, with someone watching them, and just explore both levels and take your time in there. I happily spent 30 minutes just wandering, and it is an oasis in the airport.