Tokyo is the most populated of Japan's 47 prefectures. Mainland Tokyo is divided into two sections: Western Tokyo and the special wards of Tokyo. The prefecture's tallest structures are within the 23 special wards, which comprise the area formerly incorporated as Tokyo City. As of May 2025, there are over 200 structures in Tokyo that stand at least 150 metres (490 ft) tall, of which 49 are at least 200 metres (660 ft) tall, including those that are still under construction but have been topped out. Most of these structures are buildings; however, there are other types of structures among the tallest in the prefecture, such as freestanding towers and incineration smokestacks.