The Château de Luc was built in the 12th century on a previous Celtic site. The castle, as a strategic point between the two provinces of Gévaudan and Vivarais, guarded a link to the south of France of the Auvergne frequently used by pilgrims of Saint Gilles, also known as the Regordane Way, on which it was a toll-gate.
For the first 100 years or so of its existence it was the home of the Luc family. In the 13th century it became the property of other regional seigneurs. During the Hundred Years' War it withstood a number of sieges. During the 16th century Wars of Religion the state of Gévaudan garrisoned the castle. Around 1630 the castle was dismantled under orders of Richelieu. During the period surrounding the French Revolution it continued to fall apart from neglect.
It remains in ruins today and attracts hikers who re-trace Stevenson's route on the GR 70.
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.