The Green Gate (Brama Zielona) is one of the city's most notable tourist attractions. With the Golden Gate and the Highland Gate, the Green Gate spans the Long Market and Long Street, together comprising the Royal Route. The Green Gate was clearly inspired by the Antwerp City Hall. It was built 1568-1571 as the formal residence of Poland's monarchs. It is a masterpiece by Regnier (or Reiner van Amsterdam), an Amsterdam architect, and reflects Flemish architectural influence in Gdańsk. Hans Kramer likely participated in its construction.
On 11-20 February 1646 the future Queen of Poland, Marie Louise Gonzaga, was entertained here. In the late 18th century the Nature Society was housed here, but soon moved to the Naturalists' House.
Today the Green Gate houses the National Museum in Gdańsk. Exhibitions, meetings, conferences and shows are held here. The Gdańsk office of former Polish President Lech Wałęsa is located in one of the rooms.
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.