This location is the headquarters of the American Horticultural society, one of the country's oldest gardening organizations. Founded in 1922, it exists to provide gardening and horticulture information, upholds standards of social responsibility and works in the interest of environmental stewardship. The headquarters is located on the River Farm property that once belonged to George Washington. It is between Mt. Vernon and Old Town Alexandria, and features 25 acres of gardens, grounds and picnic areas overlooking the Potomac. It is open to the public on weekdays and Saturdays in the spring and summer. Admission is free, but donations are always appreciated. Group activities are welcome but parties should make a reservation. A schedule of activities and events is available on the organization's website.