The Onze-Lieve-Vrouwetoren ('The Tower of Our Lady') is a Late Gothic church tower which is 98.33 metres tall and reaches high above the inner city. It's one of the most eye-catching monuments in town and the third highest church tower in the Netherlands. The church that belonged to the tower was destroyed by a gunpowder explosion in the 18th century.
The first chapel on site was constructed on this site in the 14th century. In the 15th century the chapel was replaced by new church with three aisles. When the tower was built is not exactly known. Construction started around 1444 and was finished around 1470. The official documents of the construction were destroyed by the Protestants in 1579 during the reformation and the ensuing iconoclasm. The church and tower were taken over by the Protestants and no longer belonged to the Catholics.
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.