Yōrō Keikoku Okukiyosumi Prefectural Natural Park

Yōrō Keikoku Okukiyosumi Prefectural Natural Park (県立養老渓谷奥清澄自然公園) is a Prefectural Natural Park in southern Chiba Prefecture, Japan. First designated for protection in 1935, the park's central features are the Yōrō Valley (養老渓谷) and Kiyosumi Mountains (清澄山地). The park spans the municipalities of Ichihara, Kamogawa, Kimitsu, and Ōtaki.