恩賜上野動物園
The pond's shape until the beginning of the Meiji Era was very different from now, in particular the northern part where the Ueno Zoo is, which was much wider. At the time, the Aizomegawa flowed into it. In 1884 however, a cooperative horse racing company, wanting to open a racing track, had the pond partly filled, bringing it to the present shape and size. The first horse race took place in the November of the same year in the presence of the Emperor, and until 1892 races took place every spring and summer.