Oregon Caves National Monument and Preserve
Oregon Caves National Monument and Preserve is a protected area in the northern Siskiyou Mountains of southwestern Oregon in the United States. The 4,554-acre (1,843 ha) park, including the marble cave, is 20 miles (32 km) east of Cave Junction, on Oregon Route 46.
Source: Wikipedia — Oregon Caves National Monument and Preserve (CC BY-SA 4.0)