The Roman catacombs, dated to the early third century, are characterized by regular plans that made the best use of available space. In the late third and fourth centuries, the catacombs grew in number and extent through the establishment of new areas. Beginning in the fifth century, the Roman catacombs ceased to be the usual places of burial and become instead spaces dedicated to the cult of the martyrs. The catacombs of the Italian peninsula and the larger islands of the Mediterranean, Greece, and Roman Africa, dated usually between the fourth and fifth centuries, are fewer and smaller than those in Rome, but are distinct in their plans and adaptation to different environments.