Mito (pop. 246,000) is the capital of Ibaraki prefecture.
The only reason to come here is for the Kairaku-en Garden (偕楽園), one of Japan's three finest (along with Okayama's Koraku-en and Kanazawa's Kenroku-en).
Tokugawa Nariaki, a relative of the shōgun laid the 18-acre garden in 1842. The best season to view it is when plum trees are blossoming, which coincides roughly with the Mito Plum Festival (水戸梅祭) is held from 20th February to 31st March each year.
How to get there
The JR Limited Express Super Hitachi from Tokyo's Ueno station or Fresh Hitachi from Tokyo's Nippori station both take 80 minutes to reach Mito (about ￥2000).
From Chiba, you go to Funabashi, then take the Tōbu Noda line to Kashiwa (about 30min), from where you can catch the JR Limited Express Super Hitachi for one more hour. A one-way trip from Funabashi is about ￥2200.