The central pond, named Himuro-ike Pond, is known for its water lilies, and during the Heian period, the ice that formed on the pond would be presented to the imperial court on the second day of the first month and its thickness would be used to predict the success of the harvest.
中心を占める池は氷室の池といい蓮で知られており、平安時代には1月2日にここに張った氷を宮中に献上してその厚さによって五穀豊穣を占ったと言われている。