George L. Carder House, also known as Boxwood Hill, is a historic home located at Castleton, Rappahannock County, Virginia. It was built about 1833, and is a two-story, Federal-style brick dwelling on a limestone foundation. It features a pair of front entrances and an original kitchen built into the cellar. The property also includes a contributing one-room log house, log shed, and wood-framed barn.

It was added to the National Register of Historic Places in 2004.