The Gardens at Alirium is a magical destination. You rez into The Gardens, a self contained Sim, in a dark space full of neon flying butterflies. You must then (at least I did) fall through the white hole below to enter the gardens, which is actually a store for plants contained inside a gigantic tree. You do not realize that you have been inside this tree until you begin to explore The Gardens outside the tree, consisting of many seasons and botanical themes all united by waves of bright light emanating form within the tree itself.
A great place to visit with a design unique to anything else I have seen in Second Life. Here is the link to visit the destination: