These world-famous gardens offer thousands of varieties of plants. But Kew is no mere pleasure garden -- it's essentially a vast scientific research center that happens to be beautiful. The gardens, on a 120-hectare (300-acre) site, encompass lakes, greenhouses, walks, pavilions, and museums, along with fine examples of the architecture of Sir William Chambers. Among the 50,000 plant species are notable collections of ferns, orchids, aquatic plants, cacti, mountain plants, palms, and tropical water lilies.

No matter what season you visit Kew, there's always something to see. Gigantic hothouses grow species of shrubs, blooms, and trees from every part of the globe, from the Arctic Circle to tropical rainforests. Other attractions include a newly restored Japanese gateway in traditional landscaping, as well as exhibitions that vary with the season. The newest greenhouse, the Princess of Wales Conservatory (beyond the rock garden), encompasses 10 climatic zones, from arid to tropical, and boasts London's most thrilling collection of miniature orchids. The Marianne North Gallery (1882) is an absolute gem, paneled with 246 different types of wood that the intrepid Victorian artist collected on her world journeys; she also collected 832 paintings of exotic and tropical flora, all of which are displayed on the walls. Afternoon tea is offered at the Orangery, and there's no better place in the gardens to sit and soak in the beauty. The Visitor Centre at Victoria Gate houses an exhibit telling the story of Kew, as well as a bookshop.