This is a large castle garden. The pond and garden were constructed by the fourth lord Ii Naooki in 1677. It was designed and named after the garden of the detached palace belonging to the Chinese emperor, Xuan Song (Tang Period). It is a famous garden, typical of the early Edo Period.

Hoshodai
... was named to convey the meaning of an excellent commanding height where the Chinese phoenix soars up toward the sky. The "Hoshodai" was painted and listed as one of the ten scenic places of natural beauty of Genkyu-en Garden in the picture of "Genkyu-en Zu" painted in Edo Period.
Boats decorated glamorously at the foot of the hills were drawn, and at times the feudal lord makes merry with boat-sailing were also depicted in the illustration.