城山公園は館山市街の南側丘陵に位置し、この地にはかつて戦国時代の武将、里見氏の居城がありました。公園内は、椿・梅・桜・ツツジ等の花木が小径をうずめ、季節に合わせて見事に咲き誇ります。山頂には天守からの眺めが楽しめる三層四階天守閣様式の館山城（八犬伝博物館）、中腹の館山市立博物館本館と併せて歴史の散策が楽しめます。

Located on a hill in southern Tateyama City, Shiroyama Park is a place where civil-war time lord Satomi once built his residence. Today the park is known as a flower viewing spot, from camellias, plums, cherries, to azaleas. On the top exists a four-story keep tower style Tateyama Castle, which has a Hakkenden museum inside. Together with Tateyama City Museum at the bottom of the hill, visitors can stroll around and learn the history of the area.