Arden, Ardentown, Ardencroft (collectively know as the Ardens) are a trio of villages/art colonies in New Castle County, Delaware. Arden, the oldest, was founded in 1900 as a radical Georgist, single-tax community by sculptor Frank Stephens and architect Will Price. Two adjoining villages of similar size were also founded on Georgist principles: Ardentown, in 1922, and Ardencroft, in 1950. The tax structure of the Ardens is based on the Single Tax economic philosophy of Henry George. As a result, a person's house is not taxed, only the land it sits on, which is administered by their respective trusts. Half the land in the Ardens is woods and open spaces. Common natural spaces include: Sunnyside Nature Preserve, Sherwood Forest with Perkins Run, The Arden/Ardentown Woods with Naaman's Creek, The Arden Green, The Pettit Green, The Henry George Green, and more. Footpaths criss-cross the villages, and paths abound in the forests, allowing full access and enjoyment of natural spaces. In 2003, the three villages were listed on the National Register of Historic Places as the Ardens Historic District. The Ardens are a Community Forest in the Old-Growth Forest Network. Arden's forests encircle the three historic villages of Arden, Ardentown and Ardencroft. All together, the forested areas, which encircle the three villages, add up to 100 acres--some protected since 1900, at Arden's founding. Arden has been listed as a Tree City, USA since 2008.