Eden Project, England
Located in Cornwall, in Southern England, this unique collection of gardens is not your typical conservatory. The translucent domes look like they came from the set of a sci-fi film. These odd-looking structures are home to self-contained biomes with plant life from tropical and Mediterranean climates. A number of outdoor gardens are also part of the complex.
The Rainforest Biome is focused on tropical plant life from many of the warmest regions of the world. An aerial walkway inside this biome provides the infrastructure for one of the only indoor canopy tours on Earth. A waterfall and free-flying butterfly population make this one of the most memorable gardens on this list, an attraction with enough spectacle that it will appeal to those who are not necessarily interested in plant life.