The Shinobazu Pond is a pond within Ueno Park, and a historically prominent Shitamachi feature often appearing in history and works of art. The park occupies the site of the former Kan'ei-ji, a temple closely associated with the Tokugawashōguns, who had built it to guard Edo Castle against the northeast, a direction believed to be unlucky by traditional geomancy. The temple was destroyed during the Boshin War. The pond, although modified many times and even once drained, is natural.
Position and Dimensions
Situated in the south of Ueno Park, the pond is divided in three sections, one called Lotus Pond because of the plants that during the summer completely cover its surface, one called Boat Pond from the rental boats it hosts, and the third called Cormorant Pond, which lies within the limits of the Ueno Zoo and takes its name from the birds that inhabit it. The pond has a circumference of about 2 km and a surface of about 1,100,000m2. To the north it borders with the Ueno Zoo, to the east with Keisei Ueno Station, to the south and to the west with Shinobazu Dori. At its center lies Benten Island on which stands the Benten-dō, a temple dedicated to the goddessBenzaiten. The park is divided in three parts by two promenades.
Name
Surface（10,000m2）
Average Depth（cm）
Water volume（1000m3）
Boat Pond
30
86
26
Lotus Pond
55
84
46
Cormorant Pond
25
92
23
Origin of the name
According to the stone inscription on Benten Island, the area between the Ueno Plateau and the Hongo Plateau used to be called Shinobugaoka, and the pond just took its name from it, but there are alternative theories. According to one, the early name Shinowazu due to the presence of bamboo grass later turned into Shinobazu. Another claims the name comes from the habit of young men and women to meet secretly here.
History and Changes
In the Jōmon period the entire place used to be just a cove of Tokyo Bay. Later, some centuries into the Common Era, the sea withdrew, leaving behind extensive marshes that covered most of the old Shitamachi. The pond is what remains of those marshes. We know that by the 15th Century the present name was already in use. In 1625 the Edo shogunate had the Kan'ei-ji built here as a counterpart to Hieizan's Enryakuji in West Japan. The temple's founder Jigen Daishi, liking Lake Biwa, had Benten Island built in imitation of Chikubushima, and then the Bentendo on it. At the time the island was accessible only by boat, but later a stone bridge was added on the east, making it possible to walk to it. 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. In 1907 the Kangetsukyō Bridge was built toward the west in occasion of the Tokyo Industrial Fair, making it possible to walk across the whole pond. In 1929 more work divided the pond in four distinct parts. The boat rental business, which continues to the present day, was started in 1939. Today's Cormorants Pond is the result of the fusion of two of those four sections. During World War II water was pumped out and the pond divided into rice paddies (the so-called Shinobazu Tanpo. There was later, among others, a plan to build a baseball field on it, but in 1949 it was decided to return the pond to its original form which we still see today. In September 1967 a hole was opened by accident in the pond during the construction of Tokyo Metro Chiyoda Line, and approximately 30 thousand tons of water flowed away. In the years between 1990 and 1994, the city authorities installed water purification equipment.
Nature
Birds
The pond hosts several dozens of types of migratory and stationary birds, whose number at times is over ten thousand. Among them particularly numerous are tufted ducks, pochard, and northern pintails.
Fish
The pond contains numerous species of fish.
Plants
The lotuses of Lotus Pond, fully grown in summer, cover the entire surface of the water, hiding it almost completely.
Other Fauna
In June 2006, alligator snapping turtles, which are a non-native species, were found in the pond, and there is the possibility that they are breeding. Since then, authorities have posted warnings against alligator snapping turtles and snapping turtles.
