Since opening in 1969, the Saitama Prefectural Museum of the Sakitama Ancient Burial Mounds (formerly known as the Sakitama Museum) has been actively involved in the preservation and maintenance of the Sakitama Kofun Cluster, a nationally designated historical site consisting of ancient burial mounds, and related projects. To restore and preserve what the Sakitama Kofun Cluster looked like when it was first constructed, the Museum researches and collects materials regarding the historical site and houses many of the artifacts discovered during excavations. Two categories of artifacts are introduced here: some of the burial accessories that were discovered at the main site (the burial mound) of the Inariyama Kofun and later designated as national treasures, and a particular type of earthenware called haniwa, figures characteristic of the Kofun Period that were arranged on top of the burial mounds or in rows along nearby ditches and moats. These artifacts are extremely valuable resources in understanding the ancient history of Japan.