From Odaiba you can see the horizon of Ariake, a neighboring man-made island. Alternatively it is called the Rinkai Fukutoshin Area meaning Tokyo Waterfront City. The mushroom-shaped dome in the center is the Ariake Sports Center. The complex features a gym, pool plus basketball and volleyball courts. The tower next to it is not a skyscraper but a former incinerator smokestack. Despite the extensive commercial and public development in these areas since the 1990s, a considerable amount of vacant acreage exists. They have been slated to provide twenty venues for the 2020 Tokyo Olympics.