The so-called Powder Tower originally served as one of the Riga defensive system buildings. There is no information on the exact date of the construction, but the first tower on this place was built in the 13th century. The name of a tower - Powder, has appeared later. In documents for the first time this place has been mentioned in 14th century by the name of Sand tower. The modern tower has been constructed on a boundary of 15th and 16th centuries. During the centuries it has been collapsed and later restored. The entrance of the tower was at the height of 5 meters, and it was possible to get to a tower only having walked upstairs.
After the Great Northern War the Powder Tower lost its military value. Tower reconstruction was began in the end of 19th century. The new pointed roof has been constructed. Last time the tower has endured reconstruction after the First World War when the Military museum of Latvia has been situated in it.
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.