Yokote Castle is said to have been built around 1570 by the warlord Onodera Terumichi. After the Battle of Sekigahara, Yoshinobu Satake, who had been transferred from Hitachi Province (Ibaraki Prefecture) to Dewa Province (Akita Prefecture), set the castle as an important stronghold in the southern part of his domain until the end of the Edo period (1868), and the Date, Suda, and Tomura clans ruled Yokote as retainers of the castle. 

The castle fell in the Boshin War in 1868, but was later redeveloped as Yokote Park, and in 1965, a castle tower-shaped observatory (commonly known as Yokote Castle) was built on the site of Ninomaru and loved by the citizens as Oshiroyama (an honorific name). 

From the observatory room on the 4th floor of the Yokote Park Observation Deck, you can enjoy a panoramic view of the vast Yokote Basin, the Yokote River, and the majestic Mt. Chokai throughout the four seasons. The first to third floors are used as a local museum, where art, crafts, ceramics, and historical materials related to Yokote City are displayed. Visitors get to know about the culture of Yokote. 

Although the museum is closed during the winter, it is temporarily open during the Yokote Snow Festival (Kamakura) held in February, and visitors can enjoy the lights of various sizes of Kamakura (Japanese Igloo) found in the city and on the riverbanks.