Built in 1842 for Nathaniel Clarke. The Castle is the focal point for Marietta Country in Oklahoma. It has been used for many prominent and influential individuals and their families throughout the years. Clarke did not live in the castle very long. In 1858, Clarke sold the Castle to John Newton. In 1887, the Castle was then sold for a mere $7,000.

Until 1992, the Castle passed through many prominent families in the area. In 1992, the Castle was declared "as an historical asset for the City of Marietta with such asset to be used for educational and public purposes." In 1994, the Castle opened to the public as an educational facility.

The Castle is open weekdays 10:00 a.m. until 4:00 p.m. and weekends 1:00 p.m. until 4:00 p.m. Tours last approx. 50 minutes. Admission is $6.00 for adults, $5.50 for senior citizens, and $3.00 for those between the ages of 3 and 17.