The Penrhos Feilw Standing Stones are a pair of standing stones on Holy Island west of Anglesey in north-west Wales. They are thought to date from the Bronze Age but their origins and purpose are unclear. They are about 3 m high and are a similar distance apart.
The stones are located behind the farmhouse of Plas Meilw. Little is known about the history of the stones. They are believed to be between 3,500 and 4,000 years old and are a Scheduled ancient monument.
The stones are in the care of Cadw; the site is open to the public throughout the year, except around Christmas and the New Year, free of charge. Access is through a kissing gate and across a grassy field, and there is a pull-in by the roadside, large enough for a single car.
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.