The Christianization of sites that had been pagan occurred as a result of conversions in early Christian times, as well as an important part of the strategy of Interpretatio Christiana ("Christian reinterpretation") during the Christianization of pagan peoples. The landscape itself was Christianized, as prominent features were rededicated to Christian saints, sometimes quite directly, as when the island of Oglasa in the Tyrrhenian Sea was christened Montecristo.
In the first centuries of Christianity churches were either house churches in whatever houses were offered for use by their owners, or were shrines on the burial-sites of martyrs or saints, which following the usual classical practice were invariably on the (then) edges of cities - the necropolis was always outside the polis. In Rome the early basilica churches of St. Peter's, Saint Paul Outside the Walls and San Lorenzo fuori le Mura, all follow this pattern. This distinction was gradually broken down, perhaps earliest in Roman Africa, as relics of the saints came to be kept in city-centre churches. By the 6th century bishops were often buried inside their cathedral, and other Christians followed.
Given the plethora of worship locations for various cults, many had fallen into disuse well before the rise of Christianity. The establishment of a third century Roman military camp in the temple complex at Luxor demonstrates an ongoing process of adaptive re-use. Obsolete temples often had their stone elements repurposed for use in new construction. Many ancient accounts of the manner of conversion of non-Christian places of worship into churches are not borne out by subsequent on-site archaeology.
After the Peace of the Church, the old pagan temples continued to function but gradually fell into disuse, and were finally all closed by the decrees of Theodosius I at the end of the 4th century. Initially they were shunned by Christians, perhaps because of their pagan associations, but also because their shape did not suit Christian requirements: "To the early Church, only one sort of building seemed suitable for christianization: the basilica", which had previously always been a secular type of building.