The archaeology of Aphrodisias in its later period, from the third to the sixth century, is particularly dense outside the monumental city centre in the residential parts of town, at the new city walls, and in the cemeteries. A variety of houses have been excavated, mostly of the late Roman period. They range from more modest, outlying houses built against the south city-wall, to compact town houses near the Tetrapylon, to great mansions with peristyles and spacious apsidal halls. One such mansion lies to the north of the Temple (the North Temenos House) and another, more impressive, adjoins the Sebasteion (the Atrium House). The core of the Atrium House was a monumental Ionic tetrastyle court or four-columned atrium dating back to the early empire. The house was re-modeled several times and in the fifth century was equipped with fine mosaics and an extraordinary series of marble shield portraits.