舘の山公園, Park on the site of a former castle in Iizaka, Fukushima, Japan

Tatenoyama Park is a scenic park in the Iizaka-machi district of Fukushima City, laid out in 1880 on the site of Otori Castle. A walking trail circles the castle ruins on the hill, and a flower-peach grove occupies one corner of the grounds. Iizaka Baseball Stadium and Otori Junior High School stand directly to the east.

The park opened in 1880 on the site of Odori Castle, a hilltop fort said to have been built in 1157 by Sato Motoharu, father of the Sato brothers who served Minamoto no Yoshitsune. Tradition holds that the castle fell in 1189 to Minamoto no Yoritomo's Oshu campaign, after Motoharu buried a crane on the summit and prayed for victory. Excavations on the summit in 1995 unearthed 14th-century imported ceramics.

The park occupies the site of Ōtori Castle, said to have been built in 1157 by Satō Motoharu under Fujiwara no Hidehira's orders. A legend holds that Motoharu buried a crane at the hilltop headquarters and prayed for victory, vowing its spirit would become a great bird (ōtori) to block the enemy. The castle fell to Minamoto no Yoritomo's forces in 1189.

The park lies west of Iizaka's town centre in Fukushima; the grounds are on the hill of the former Ōtori Castle, with a walking route around the castle site. Iizaka Stadium and Ōtori Junior High School stand immediately to the east. The hilltop is reached on foot, so allow time for the climb.

The hilltop main enclosure of the former Ōtori Castle yielded imported ceramics from the 14th century in a 1995 excavation, suggesting later rebuilding on the site. Legend holds that Satō Motoharu buried a crane at the summit and prayed for victory before the castle fell to Minamoto no Yoritomo's forces in 1189.