Toshima no Mori is a rooftop garden on the 10th floor of the Toshima City Office in Higashi-Ikebukuro. A small stream runs from the 10th floor down to the 4th, with different elevations and plants on each level. Entry is free, and the garden is reached by elevator or an outdoor staircase. It also has an aquarium with fish and a medaka biotope, and the garden itself is not large.