Las Bóvedas (the domes) is the local name for the remains of some Roman baths near San Pedro de Alcántara in Andalusia, near Marbella. They are located close to the Paleo-Christian Basilica, Vega del Mar. Historians are still unsure of the baths' true origins, though most believe that they are all that remain of the Roman settlement known as Cilniana (or Silniana) destroyed by an earthquake in 365 AD. They can be visited along with the better conserved Villa Romana (Roman villa).
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.