The Vatican Gardens have been a place of quiet and meditation for the popes since 1279 when Nicholas III moved his residence back to the Vatican from the Lateran Palace. Within the new walls, which he had built to protect his residence, he planted an orchard (pomerium), a lawn (pratellum) and a garden (viridarium).
Created around the hill of Saint Egidio (where the Palazzetto del Belvedere is located today) and the courtyards of the Vatican Museums, this was to be the first garden in the Vatican. However, should you visit the Vatican Gardens today you would begin by viewing a totally different area from that first orchard, one located in a more recent addition to what is now Vatican City State. It is there that larger and more recent gardens have been planted, covering together with the original garden about half of the 44 hectares of Vatican City.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.