Dumbarton Oaks is one of the most unusual and special places in Washington DC. It has spectacular gardens as well as a world-class Pre-Columbian Collection, Byzantine Collection and a Renaissance Music Room that takes one's breath away! The museum is free (although there is a fee for the gardens). It is located in upper Georgetown. It is now owned by Harvard University and also houses a research center. It should not be missed. I would not suggest the museum for young children, although people of any age will enjoy the gardens.