The stone carvings of Val Camonica (Camonica Valley) constitute the largest collections of prehistoric petroglyphs in the world. The collection was recognized by Unesco in 1979 and was Italy's first recognized World Heritage Site. Unesco has formally recognized more than 140,000 figures and symbols, but new discoveries have increased the number of catalogued incisions to between 200,000 and 300,000. The petroglyphs are spread on all surfaces of the valley, but concentrated in the areas of Darfo Boario Terme, Capo di Ponte, Nadro, Cimbergo and Paspardo.
Many of the incisions were made over a time period of 8000 years preceding the Iron Age (1st millennium BC), while petroglyphs of the last period are attributed to the people of Camunni, mentioned by Latin sources. The petroglyph tradition does not end abruptly. Engravings have been identified (although in very small number; not comparable with the great prehistoric activity) from the Roman period, medieval period and are possibly even contemporary, up to the 19th century. Most of the cuts have been made using the 'martellina' technique and lesser numbers obtained through graffiti.
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.