Warsaw: If you have more time...
Warsaw Barbican and City Walls, Warsaw / Shutterstock
Barbican and City Walls
Dating back to 1548, the defensive fortifications were built according to a design by the architect Jan Baptist the Venetian.
Unfortunately, though, right from the beginning, it didn't fulfil its defensive function due to the development of artillery. Only once did it take part in a battle - during the Swedish Deluge it was retaken by the Polish Army from the hands of the invaders. In the 19th century, what was left of the Barbican (which had been rebuilt) was adapted to the newly built townhouses.
Just before the outbreak of World War II a decision was taken to reconstruct some of the walls and part of the Barbican Bridge. The work was directed by Jan Zachwatowicz. Unfortunately, it wasn't finished due to the war. It was destroyed in 1939, but later rebuilt in 1952-54.
The Warsaw defensive walls date back to the 1st half of the 14th century and are about 1200 metres long and cover an area of about 8.5 hectares. The first fragment of about 300 metres is located between today's Wąski Dunai Street and Krakowska Brama. After 1379, work was started on walls from the side of the Vistula.