Emilio J. Rodríguez Posada, CC BY-SA 3.0 , via Wikimedia Commons
Cádiz is an ancient port city in the Andalucia region of southwestern Spain. The home of the Spanish Navy, the port boomed in the 16th-century as a base for exploration and trade. It has more than 100 watchtowers, including the iconic Torre Tavira, which was traditionally used for spotting ships. On the waterfront is the domed, 18th-century Cádiz Cathedral, featuring baroque and neoclassical elements.