The Oosterkerk ('eastern church') is a Dutch Reformed church built in the period 1669-1671 by architect Daniël Stalpaert and completed by Adriaan Dortsman. The church bells were cast by Pieter Hemony. The church has not been used for church services since 1962, and fell into decay since then. It was restored in the 1980s.
The layout of the church is in the shape of a Greek cross in which the space between the arms has been partially filled by lower volumes. On the canal side is the main entrance, the elevation of which is supported by a balustrade. The cornice of the lower volumes follows the relief of the walls, whereas the cornice of the Greek cross strictly conforms to the layout without acknowledging the indentations of the wall.
Some 500 people were buried in the church, including Adriaan Dortsman.
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.