Dover is a coastal town in England’s southeastern county of Kent. It’s a major port for ferries to Calais, in France. Built to repel invasions from across the English Channel, medieval Dover Castle overlooks the town and houses the extensive Secret Wartime Tunnels.

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.

Palma is a resort city and capital of the Spanish island of Mallorca (Majorca), in the western Mediterranean. The massive Santa María cathedral, a Gothic landmark begun in the 13th century, overlooks the Bay of Palma. The adjacent Almudaina is a Moorish-style Arab fortress converted to a royal residence. West of the city, hilltop Bellver Castle is a medieval fortress with a distinctive circular shape.

Toulon is a port city on southern France’s Mediterranean coast, lined with sandy beaches and shingle coves. It’s a significant naval base and the harbor is home to submarines and warships, as well as fishing boats and ferries. The grand Musée National de la Marine in the Port of Toulon exhibits maritime artifacts. Rugged limestone mountains form a backdrop to the city, and a cable car shuttles visitors up Mont Faron.

Almería is a city in southeast Spain. The Alcazaba is an imposing Moorish fortress overlooking the city. The fortified, 16th-century Almería Cathedral has a Gothic ribbed ceiling. The Museum of Almería displays archaeological finds from across the region. Underground lies a network of tunnels, the Civil War Shelters of Almería. The English Cable is a huge iron pier and symbol of the city’s former mining industry.

Lisbon is Portugal’s hilly, coastal capital city. From imposing São Jorge Castle, the view encompasses the old city’s pastel-colored buildings, Tagus Estuary and Ponte 25 de Abril suspension bridge. Nearby, the National Azulejo Museum displays 5 centuries of decorative ceramic tiles. Just outside Lisbon is a string of Atlantic beaches, from Cascais to Estoril.

Dover is a coastal town in England’s southeastern county of Kent. It’s a major port for ferries to Calais, in France. Built to repel invasions from across the English Channel, medieval Dover Castle overlooks the town and houses the extensive Secret Wartime Tunnels.