Home or house for the dead. The term is applied loosely to all kinds of graves, funerary monuments, and memorials. Prehistoric tomb burial mounds, or barrows (artificial hills of earth and stones piled over the remains), were usually built around a hut containing personal effects for use in the afterlife. Burial mounds were a prominent feature of the Tumulus period in Japan (3rd–6th century); these often spectacular monuments consisted of earthen keyhole-shaped mounds surrounded by moats. Burial mounds, sometimes shaped like animals, were characteristic also of Indian cultures of eastern central North America c. 1000 BC–AD 700. With more advanced technology, brick and stone tombs appeared, often of imposing size. In Egypt tombs assumed great importance, especially in the form of pyramids. In medieval Christian thought, the tomb became a symbol of a heavenly home; this concept appeared in the Roman catacombs, whose walls display scenes of paradise. Since the Renaissance, the idea of the tomb as a home has died out in the West, except as a faint reminiscence in the mausoleums or vaults of modern cemeteries. See alsobeehive tomb, cenotaph, mastaba, stele.