I get a lot of requests from people planning trips to Japan asking for places they should visit. For visits to the Kanto (Tokyo and Yokohama) area, one spot I always recommend is Kamakura, a charming city that's a 90 minute train ride away from Yokohama, great for taking a day trip. A picturesque city by the sea with a very long history, it hosts many temples and shrines, the most famous being the Tsurugaoka Hachimangu Shrine founded in 1063. Old stuff like this always floors me as an American, since nothing in the U.S. built by Europeans is half that old. Kamakura is most famous for the giant bronze statue of Buddha, the second largest in Japan, and this alone would make the city worth a trip even if it weren't one of the prettiest places in the country to visit. Kamakura is also home to one of the most famous train lines in Japan, the Enoshima Electric Railway (nicknamed "Enoden"), which has been in operation since 1900 and which is beloved by Japan's many train otaku, who come from miles away ride on it. (Watch the yuri anime Aoi Hana to see more of the beautiful Kamakura area and Enoden train line.)
The Great Buddha of Kamakura, the 2nd largest in Japan.