The Dolmen de Soto is a Neolithic subterranean structure in Trigueros, Andalucía. It is estimated it was built between 4,500 and 5,000 years ago and is one of about 200 neolithic ritual-burial sites in the province of Huelva.
On the surface it resembles a circle-like mound with a diameter of 75 metres. It has a V-shaped passage 20.9 metres long. In the eastern end of the passage there is a chamber. During the equinox, the first sun lights the interior of the passage and the chamber for some minutes, and it is assumed this was to denote an eventual re-birth of the buried. Several of the standing-stones have engravings, and it is viewed as one of the largest dolmens in Spain. The passage has 31 standing-stones in the northern part of the passage and 33 in the southern part. The standing stones are of quartzite, sandstone, and limestone and carry 20 capstones that make the roof of the passage.
Each of the discovered eight buried bodies were in fetal position and had their respective artifacts beside them. Daggers, cups, and marine fossils were discovered. The artifacts found were not as abundant as those found in other sites; therefore, it is assumed that the Dolmen de Soto was not used for a long time. Engravings were found on 43 standing stones and describe humans, cups, knives, and geometric forms such as simple lines or circles.
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.