Step into the tropics inside a greenhouse
On a rainy or cold day, a greenhouse lets you walk among huge tropical leaves and flowers in warm, humid air. Around Tokyo there are glasshouses at botanical gardens, at a university garden and even at a butterfly house. Many of them are closed on Mondays, so check the day before you go.
A tropical plant museum with three large glass domes, where you walk from a waterside jungle of palms and ferns to plants of the Ogasawara Islands, a remote subtropical island chain that is part of Tokyo. The domes are warmed with heat from the waste incineration plant next door. Afterwards you can step out onto the wide lawns of Yumenoshima Park, a short walk from Shin-Kiba Station.
A large botanical garden in western Tokyo whose big greenhouse has rooms of tropical flowering trees, tropical water lilies and begonias, about 1,300 kinds of plants in all. The garden also has a large rose garden, and Jindaiji, an old temple known for the soba noodle shops around it, is just outside. It is a bus ride from Chofu Station, and the garden is closed on Mondays.
The public greenhouse of the University of Tokyo's botanical garden, which began in the 1600s as the shogun's herb garden. Six rooms hold tropical and subtropical plants, from desert plants and orchids to rare plants of the Ogasawara Islands. The greenhouse opens for shorter hours than the garden, so see it first and then walk the wide grounds.
A small nature center in Adachi, northern Tokyo, with a two-story greenhouse where butterflies fly freely all year. Even in winter you can watch them land on flowers right beside you, and there are also displays of insects, fish and other small animals.
A prefectural flower garden in Kamakura with a glasshouse of tropical plants, plus flower beds and lawns that change with the seasons. It is about 15 minutes on foot from Ofuna Station, roughly 45 minutes by train from Tokyo.