A large group of early twentieth-century mansions is nestled among the steep slopes and winding roadways of Massachusetts Heights, a narrow corridor between 34th Street and Massachusetts Avenue to the east of the Naval Observatory that was first developed in 1911. Like their more modest contemporaneous counterparts in many other areas of the city, these mansions ranged widely in style and materials. Although most of its neighbors were inspired by English architectural prototypes, none is as intensely English as the Arthur S. Henning House, where the complementary relationship between the gardens and sprawling residence is reminiscent of small Edwardian estates. With an end wall facing the street and the main entrance masked by a pergola, glimpses of discrete parts of the picturesquely composed, L-shaped house were planned to create the impression of an old and venerable estate slowly built over time. The wing farthest from the street has a conical tower set in front of the main rectangle, both constructed in Elizabethan black and white exposed half timbering. Set at a right angle to it is a gabled, two-story wing with a simple scalloped bargeboard in brick and a large end chimney; the rough texture of the walls comes more from the intentionally sloppy mortar joints than from the surfaces of the bricks. Irregular, slightly curved terracotta tiles that cover all the roofs contribute to the sense of the house's great age, as their varied color modulations harmonize well with the multitoned bricks. Diamond-quarreled casement windows finish the effect: a romantic and sophisticated, rustic and vernacular stage set for gracious living.