Chiba Prefecture (千葉県 Chiba-Ken)  is located directly east of Tokyo, and bordered by Ibaraki Prefecture to the north. A large part of the prefecture is made up of the Bōsō Peninsula (房総半島 Bōsō-hantō), which shields Tokyo bay from the Pacific Ocean.
Much of the western/northwestern part of Chiba is relatively uninspired urbanity and bedtowns for Tokyo, but once you get past the city and watch the sharp descent into rural countryside of sprawling rice fields, rolling hills, and striking coastlines, you will realize why Chiba has been variously called "Edo's Breadbasket", "Japan's Golf Mecca", and "Tokyo's Secret Backyard".
The area is relatively poorly known, even among Japanese people, but is nonetheless a great place to get away from Tokyo and explore a Japan a bit off the beaten track.
Chiba - eponymous capital of the prefecture, which doesn't bear much resemblance to William Gibson's depictions but has a few points of interest
Ichikawa - a small city immediately across the Edo River from Tokyo
Many parts of Chiba can be visited on a day trip from Tokyo. The Pacific coast is dotted with many traditional fishing villages, and young surfers from Tokyo are attracted by the waves. The inner coast is less picturesque, but the cliffs of Nokogiriyama are a popular tourist attraction.
While JR trains run the entire coast of Chiba, the inner coast is just a 30-minute ferry ride from Kurihama, south of Yokohama. 1997 saw the completion of the Tokyo Wan Aqua Line bridge and tunnel, which burrows under and rises across Tokyo Bay between Kisarazu (Chiba prefecture) and Kawasaki (on the Tokyo side). At ¥4000 for a passenger car, almost nobody uses the tunnel though, and it's bleeding government money. You can take highway buses through the tunnel and over the bridge from Tokyo Station, Shinagawa, Haneda Airport, Kawasaki and Yokohama stations for up to ¥1500 one way to Kisarazu.
JR East train routes in Chiba prefecture
The center of the JR network in Chiba is, unsurprisingly, JR Chiba station. But be careful when taking trains to the Boso Peninsula, as there are two different ways trains can get to Awa-Kamogawa, the final stop. The Uchibō Line (内房線), or "Inner Boso Line", follows the western coast (Tokyo Bay side) through Kisarazu, while the Sotobō or "Outer Boso" Line (外房線) cuts across the peninsula and then goes down the east coast (Pacific Ocean side) via Katsuura. Additionally, trains to Choshi can turn north at Sakura to go via Narita (the Narita Line), or go south via Naruto along the Sobu Main Line.
To summarize all that, here are the platforms to take at Chiba station:
Sobu Main Line
Narita Line, N'EX
Nokogiriyama (鋸山), meaning "sawtooth mountain", is a group of Buddhist temples cut into sheer cliffs. A rope-way gondola will take you up to the top, and on a clear day you'll have a spectacular 180-degree panorama spanning Chiba, Tokyo, and Yokohama to the north, Mount Fuji to the west, and Izu Oshima and Niijima to the south. Even on a so-so day, Yokosuka should be visible across Tokyo Bay. The most popular vantage point is Jigoku-nozoki (地獄覗き, "peering into hell") a small rock platform which sticks out over cliff. In the other direction you can see the low mountains of the interior Boso peninsula. From the peak, paths descend inland through the woods down to Nihonji (日本寺). The temple, built in 725 C.E., has a stone buddha statue that, at at total height of 31.05 meters, is in fact one of the largest buddha statues in Japan. From the Tokyo area, you can get to Nogokiriyama via the Tokyo Bay ferry from Kurihama (south of Yokohama). There are buses from the JR and Keikyu stations to the Tokyo-Wan Ferry Terminal, or you can walk (20 minutes). On the Chiba side, Kanaya is at the foot of the mountain. It should be taken into consideration that if you choose to descend the entire mountain on foot there is a long walk to the nearest rail station, the Hota JR station, with very infrequent service.
Kujukurihama beach in winter
Kujukuri-hama (九十九里浜) beach is, for many travelers, their first glimpse of Japan: it's the long coastline you see from the plane coming in over the Pacific into Narita. The name means "99-ri coast", where a "ri" is an old unit of length equal to about 654 meters. The coast is in fact around 60km in length. There are numerous small towns along the coast, from Iioka on the north to Ichinomiya on the south.
The lower Boso peninsula has several artificial attractions that are popular for family excursions but probably of limited appeal to travelers: the Kamogawa Sea World (鴨川シーワールド) marine park, Mother Farm (マザー牧場) where kids can pet farm animals, and strangest of all, the Tokyo German Village (東京ドイツ村) , with reconstructed half-timbered houses and bratwurst meals.
Nokogiriyama - huge mountain temple complex with Japan's largest pre-modern Buddha statue and gorgeous views
Narita Shinshouji Temple and surrounding traditional shopping streets