The ramparts of Quebec City are the only remaining fortified city walls in North America north of Mexico. The British began refortifying the existing walls, after they took Quebec City from the French in the Battle of the Plains of Abraham in 1759.
The wall, which runs on the eastern extremity on the Promontory of Quebec, surrounds most of Old Quebec, which was declared a World Heritage site by UNESCO in 1985. The fortifications were designated a National Historic Site of Canada in 1948.
References:Herceg Novi was founded (on a former small fishing village, existing since Roman Empire times) as a fortress in 1382 by first Bosnian King Stjepan Tvrtko I and was called Sveti Stefan or Castelnuovo. The Turks conquered Herceg Novi in 1482, and ruled for 200 years, until 1687. However, there was a short pause between 1538 and 1539 when it was held by the Spaniards before they were defeated in the Siege of Castelnuovo. Turkey ruled again until 1687, from then until 1797, the town was ruled by the Venetian Republic.
The Herceg Novi old town is amazing. It is on a fairly steep hill that leads all the way down to the sea. Wandering through the small stairways to the various plazas and fortresses is a many hour adventure.