Tokyo, formerly Edo (until 1868), is the city and capital of Tokyo as well as Japan. It is situated at the mouth of Tokyo Bay on the Pacific coast of central Honshu. Greater Tokyo is Japan's largest urban and industrial agglomeration, and it is the focal point of the vast metropolitan area known as Greater Tokyo. The city is built on low, alluvial plains surrounded by upland hills. Summers are hot and humid, while winters are mild. Early summer and early autumn are rainy seasons, with two or three typhoons occuring on a regular basis in September and October. The city is built on low, alluvial plains surrounded by upland hills. Summers are hot and humid, while winters are mild. Rainy seasons with two or three typhoons occur in early summer and early autumn common in September and October.