The Berlin Customs Wall was a ring wall around the historic city of Berlin, between 1737 and 1860; the wall itself had no defence function but was used to facilitate the levying of taxes on the import and export of goods (tariffs) which was the primary income of many cities at the time.
Wall monument made from excavated stones
Leipzig Gate/Potsdam Gate around 1830
Rosenthal Gate around 1800
Halle Gate around 1800
The Berlin Fortress was the fortification of the historic city of Berlin. Construction started in 1650. The ramparts, walls, moats and glacis of the 17th-century bastion fort ran around the historic city limits. The demolition of its ramparts began in 1740.
Berlin Fortress