The National Historic Site designation includes three outlying areas. The  has the foundations for twelve granaries that were used for storing of taxation rice. These ruins are located about 500 meters southeast of the Ōmi Provincial Capital ruins and the site was added to the designated area in 1998. The  is located 300 meters south of the south gate of the Ōmi Provincial Capital ruins. It is a smaller moated and palisaded enclosure, and contains the remains of buildings from three construction phases  in a planned arrangement. The purpose of these buildings are unknown, but as the roof tiles are identical to the roof tiles used in both the Soyama Site and the Ōmi Provincial Capital site, it is believed to contain some of the offices which made up the provincial government administration. Pottery with the words "Tempyo Shoko" and ink stones have been found as evidence for this claim. It was added to the designated area in 2005. The  consist of two building traces located to the northwest of the Aoe Site. The same roof tiles as found in the Ōmi Provincial Capital ruins have been excavated, and the position of these ruins indicates that it may have been the location of the official residence of the governor. It was added to the designated area in 2009.