Oregon Caves National Monument -
Nestled deep inside the Siskiyou Mountains, the Oregon Caves National Monument formed as rainwater from the ancient forest above dissolved the surrounding marble and created one of the world's few marble caves. The highly complex geology found on the Monument contributes to the unusual and rare plants and animals found nowhere else but here. Experience the extensively decorated and adventurous "Marble Halls of Oregon."
Local legend has it that a young woman called Elizabeth hanged herself here on her wedding night when she caught her husband with someone else. Her ghost has been seen walking the halls in the night.
Read more at Travel Oregon