Campeche, Mexico - This fortified town sits on the Yucatán Peninsula and is famous for being one of the few walled cities in South America, and the only one in Mexico.
San Marino - This tiny country is the oldest republic in the world, founded in 301. The city became a center for christian refugees fleeing Roman persecution.
San Marino - The urban center was protected by three towers. The first, named Guaita, was built to protect the city and was thought to be impenetrable. When the war continued, two more towers were built, named Cesta and Montale.
Tallinn, Estonia - The Estonian city is the best-preserved walled town on the Baltic Sea. Of the 66 original towers along the walls during medieval times, only 20 are still standing. Despite that, the architecture of this city is still well preserved.
Valença do Minho, Portugal - Valença do Minho is notable for its walls and the traces of a fortified defensive town. Nowadays the monuments dating back to the 17th and 18th centuries are still well preserved.
Ciudad Rodrigo, Spain - Ciudad Rodrigo is one of the many Spanish towns whose old town center is surrounded by city walls. The first stone was laid in the 12th century by order of Ferdinand II of León.
Masada, Israel - The remains indicate an ancient construction, historians have still been unable to identify a year of construction. In 2001 it was designated World Heritage Site status.