Sakai, in the far south-west of Ibaraki, sits on the Tone river, Japan's largest river by drainage basin, at a point where the river makes a broad sweep across the Kanto plain. In the Edo period, Sakai was a busy river port, where boats loaded with rice, soy sauce and other goods passed on their way to and from Edo, and the town grew rich on the trade.
Across the river, on a narrow tongue of land where the Edo river branches off from the Tone, stands Sekiyado, once a castle town guarding this strategic junction. A reconstructed castle keep there houses the Chiba Prefectural Sekiyado Castle Museum, which tells the story of the rivers and the efforts to control them, including the great Edo-period project that diverted the Tone eastward to protect the capital from floods. The view from the top of the keep over the rivers and the plain is excellent.
Calling this a high point is relative: the land is almost perfectly flat, and the highest ground for miles is the river embankment. But the embankments offer long views across the plain, and on clear days Mount Fuji, Mount Tsukuba and the mountains of Nikkō and Chichibu can all be seen on the horizon.
For riders, the roads around Sakai are flat and straight, with little traffic away from the main routes. The bridges over the Tone offer views of the wide river. Fuel and food are available in Sakai and the surrounding towns. It is a peaceful, unhurried place to pause on the way north.