The fortifications of Gothenburg were initially embankments along the newly dug city moat, with construction beginning in 1624 under the leadership of 2 engineers, Captain Johan Schultz and Johan Jacobssen Kuyl, following a design by chief engineer Johan Rodenburg. The works were based upon the well-established Dutch school of fortification.
When Erik Dahlberg took responsibility for Sweden's fortifications in 1676 he implemented Karl XI's wishes for modern bastions of high wall construction. The ramparts were lined with walls of blasted rock and the fortified town of Gothenburg developed with 13 polygonal bastions and accompanying moat, ravelins and 3 city gates.
Wikipedia https://en.wikipedia.org/wiki/Fortifications_of_Gothenburg
Address 26 Västra Hamngatan, Göteborg 41117, Sweden
Coordinates 57°42'6.765" N 11°57'58.017" E