Aizkraukle Castle (Ascheraden) is the ruins of a medieval castle, located on the right bank of the river Daugava. The castle was built in second half of 14th century by the Livonian Order. From 1334-1480 it was the seat of a Komtur.
In 1559, Aizkraukle was seized by the Poles and in 1577 captured by the Russians. The castle was still standing in 1633, but was in ruins by 1680. Today there are seen remnants of fundament of the castle and up to 5 metres high fragments of one wall. Picturesque ruins serve as a popular local tourist destination.
The castle should not be confused with the Old Aizkraukle Castle (Alt-Ascheraden) - another 13th century medieval castle a few kilometres downstream.
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.