8 Best Sights in Side Trips from Tokyo, Japan

This complex on the hills overlooking Hakone has more than the average onsen. In addition to all the water-based attractions, there is a shopping mall modeled on a European outdoor market, swimsuit rental shop, massage salon, and game center. The park is divided into two main zones, called Yunessun and Mori no Yu (Forest Bath). In the Yunessun side, you need to wear a swimsuit, and can visit somewhat tacky re-creations of Turkish and ancient Roman baths. You can also take a dip in coffee, green tea, sake, or red wine. It is all a bit corny, but fun. Younger visitors enjoy the waterslides on "Rodeo Mountain." In the more secluded Mori no Yu side, you can go au naturel in a variety of indoor and outdoor, single-sex baths. When signing in at reception, get a waterproof digital wristband that allows you to pay for lockers and drink machines within the complex.

Edo Wonderland, a living-history theme park a short taxi ride from downtown, re-creates an 18th-century Japanese village. The complex includes sculpted gardens with waterfalls and ponds and 22 vintage buildings, where actors in traditional dress stage martial arts exhibitions, historical theatrical performances, and comedy acts. You can even observe Japanese tea ceremony rituals in gorgeous tatami-floor houses, as well as people dressed as geisha and samurai. Strolling stuffed animal characters and acrobatic ninjas keep kids happy. Nikko Edo Mura has one large restaurant and 15 small food stalls serving period cuisine like yakisoba (fried soba) and dango (dumplings).

The largest of the recreational facilities at Lake Kawaguchi has an impressive assortment of rides, roller coasters, and other amusements, but it's probably not worth a visit unless you have children in tow. In winter there's superb skating here, with Mt. Fuji for a backdrop. Fuji-kyu Highland is about 15 minutes' walk east from Kawaguchi-ko Station. In addition to the entry fee, there are charges for various attractions, so it's best to get the one-day free pass.

Although no longer Japan's tallest building—that title now goes to Osaka's Abeno Harukas—this 70-story tower in Yokohama's Minato Mirai is the tallest in Greater Tokyo. The observation deck on the 69th floor has a spectacular view of the city, especially at night; you reach it via a high-speed elevator that carries you up at an ear-popping 45 kph (28 mph). The complex's Dockyard Garden, built in 1896, is a restored dry dock with stepped sides of massive stone blocks. The long, narrow floor of the dock, with its water cascade at one end, makes a wonderful year-round open-air venue for concerts and other events; in summer (July–mid-August), the beer garden installed here is a perfect refuge from the heat. The Yokohama Royal Park Hotel occupies the top 20 stories of the building, and the courtyard on the northeast side connects to Queen's Square, a huge atrium-style vertical mall with dozens of shops (mainly for clothing and accessories) and restaurants.

Filling galleries directly across from the Landmark Tower are rocket engines, power plants, a submarine, various gadgets, and displays that simulate piloting helicopters.

This amusement-park complex claims—among its 30 or so rides and attractions—a four story high water-chute ride. The Ferris wheel towers over Yokohama. The park is west of Minato Mirai and Queen's Square, on both sides of the river.

This museum houses a collection of roughly 3,500 dolls from all over the world. In Japanese tradition, dolls are less to play with than to display—either in religious folk customs or as the embodiment of some spiritual quality. Japanese visitors to this museum never seem to outgrow their affection for the Western dolls on display here, to which they tend to assign the role of timeless "ambassadors of goodwill" from other cultures. The museum is worth a quick visit, with or without a child in tow. It's just across from the southeast end of Yamashita Park, on the left side of the promenade.