Constructed in 1912 and completed in December of the same year, the Historical Museum for Agricultural Education is one of the few buildings still surviving as a central facility of a national professional college established in the Meiji era. It has been preserved well with little alteration and was designated as an Important Cultural Property on July 12, 1994. The Guardroom and Old Main Gate were also given the same designation at the same time. A large-scale renovation took place around that time and the Historical Museum was restored to its original state. Polan Plaza, which houses a sundial, was built to the northeast of the Hall in the corner that connects to the Faculty of Agriculture building.

The Guardroom

The Guardroom, which has an octagonal hip roof, was built in 1903 next to the Imperial College Main Gate (the current student gate). It is a historically valuable construction that dates back to the Meiji era. It was moved to its present place when the main building was constructed. This Guardroom and the Old Main Gate (including part of earthwork) were registered as Important Cultural Properties since they were recognized to be important parts of school structures during the Meiji era.

The Old Main Gate

The Old Main Gate was constructed when the main building of the Imperial College was constructed in 1912 by building a road for installation between the top and bottom platforms of the river terrace on the western side of the Historical Museum. The top platform had earthwork supported by granite block gateposts presenting a stately castle-like structure. The top of the gatepost has a lantern that resembles an old globe. Inside the gate, a gigantic tulip tree that was transplanted as a starting point of the tree-lined street in 1920 hints at what used to be a tree-lined street.

The Polan Plaza

The name is derived from Kenji's story book of the same name Polan no Hiroba (Polan Plaza). In this book, he describes a scene in which orchestras were playing music in the mysterious Polan Plaza, illuminated by the light of white Dutch clovers and the faint light of the galaxy, and songs were sung happily till morning. The Plaza represents his college days, and the former main building (Historical Museum) symbolizes those days. When the former main building was designated as an Important Cultural Property, the Polan Plaza was constructed to connect it to the present time.