Lower to its southwest was the "ninomaru," where the Ninomaru Palace stood and heirs to the domain lord resided, and the "sannomaru," which housed the Sannomaru Palace -- the lord's residence and the domain's administrative center -- along with samurai residences. After the return of land and population registers to the emperor in 1869, the Sannomaru Palace was used as the domain's administrative office, but was destroyed in a fire believed to have started in a kitchen in 1870. Subsequently, the bailey became military land, and after World War II, facilities such as a hospital and a baseball stadium were built. To pass on Matsuyama Castle, almost all of which is designated as a national historic site, to future generations, the city has developed a preservation and utilization plan. To enhance the site's historical value, it has dismantled the post-WWII facilities on the "sannomaru" site, and is conducting archaeological excavations and seeking to restore the Sannomaru Palace.