Kew Royal Botanic Gardens, London
Arguably the most famous botanic garden in the world, Kew Royal Botanic Gardens has an impressive collection of “glasshouses.” The highlight is probably the Princess of Wales Conservatory, which features gardens representing 10 climate zones, from wet tropical to arid savanna. There are orchid and carnivorous plants on display as well.
Several other indoor gardens also sit inside the confines of Kew. The Bonsai House, Palm House and Waterlily House are examples of the kind of themes you can find if you are willing to spend a day (or more) wandering around the historic grounds of this attraction, deemed impressive enough to earn designation as a UNESCO World Heritage Site.