Howaen

Howaen began as the garden of a temple, was expanded by Tokugawa Mitsukuni in the seventeenth century, and is now a small municipal Japanese garden in a residential part of Mito with a pond, a rise and a lot of hydrangeas — roughly six thousand plants across about a hundred varieties, which is a considerable density for a garden this size.

It is free and permanently open, which is the thing to know. Kairakuen, twenty minutes away, is one of Japan's three great gardens and behaves accordingly; Howaen is where people from Mito actually go, and for most of the year it is a quiet place with a pond in it. For four weeks in June the hydrangea festival brings food stalls, evening lighting and a substantial local crowd, and the adjoining temple grounds fill with people who live within walking distance.