Riga Old Town (Vecrīga) is the historical center of Riga, Latvia, located on the east side of Daugava River. Vecrīga is famous for its old churches and cathedrals, such as Riga Cathedral and St. Peter's church.
Vecrīga is the original area of Riga and consists of the historic city limits before the city was greatly expanded over the years. In the old days, Vecrīga was protected by a surrounding wall except the side adjacent to the Daugava river bank. When the wall was torn down, the waters from Daugava filled the space creating Riga City Canal.
In the 1980s Vecrīga's streets were closed to traffic and only area residents and local delivery vehicles are allowed within Vecrīga's limits with special permits. Vecrīga is part of a UNESCO World Heritage Site listed as "Historic Centre of Riga".
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.