Rotterdam: 18-Night Mediterranean from Lisbon

Lisbon cruise port is one of the most atmospheric arrivals in Europe. Ships sail up the Tagus River past the 25 de Abril Bridge (a near-twin of San Francisco's Golden Gate) and the Christ the King statue, with the city rising up on seven hills to the north.

Cadiz is the actual cruise port marketed as "Seville (Cadiz)" by cruise lines because Seville, Spain's fourth-largest city, is the primary day-trip draw from this port. Cadiz itself is one of Europe's oldest continuously inhabited cities, perched on a narrow peninsula jutting into the Atlantic on Spain's southwestern coast.

Gibraltar is a British Overseas Territory at the southern tip of the Iberian Peninsula, a 6.7-square-kilometer enclave dominated by the Rock of Gibraltar, a 426-meter limestone monolith that guards the western entrance to the Mediterranean.

Barcelona cruise port is the busiest in the Mediterranean, handling millions of passengers a year across multiple terminals. The city behind it earns that traffic.

Palma de Mallorca cruise port is one of the busiest in the Mediterranean and the main cruise gateway to the Balearic Islands. Palma sits on the south coast of Mallorca, the largest of the Balearics, about 250 kilometers south of Barcelona.

Valletta cruise port is one of the most visually dramatic arrivals on any Mediterranean itinerary. Ships sail into the Grand Harbour, a deep natural inlet flanked by honey-colored limestone walls that rise straight out of the water, with Valletta itself perched on the peninsula above.

Valletta cruise port is one of the most visually dramatic arrivals on any Mediterranean itinerary. Ships sail into the Grand Harbour, a deep natural inlet flanked by honey-colored limestone walls that rise straight out of the water, with Valletta itself perched on the peninsula above.

Messina cruise port sits at the northeastern tip of Sicily, directly across the narrow Strait of Messina from mainland Italy. Ships dock right at the city waterfront, making it one of the easiest Mediterranean ports to step off and explore.

Naples cruise port is one of the most popular stops on Mediterranean itineraries, and it's easy to see why. The city sits on the Bay of Naples with Mount Vesuvius looming behind it, and it serves as the gateway to Pompeii, the Amalfi Coast, Capri, and Sorrento.

Rome's cruise port is in Civitavecchia, a working port town about 80 kilometers northwest of the city. That distance is the single most important thing to understand about this stop.

Naples cruise port is one of the most popular stops on Mediterranean itineraries, and it's easy to see why. The city sits on the Bay of Naples with Mount Vesuvius looming behind it, and it serves as the gateway to Pompeii, the Amalfi Coast, Capri, and Sorrento.

Messina cruise port sits at the northeastern tip of Sicily, directly across the narrow Strait of Messina from mainland Italy. Ships dock right at the city waterfront, making it one of the easiest Mediterranean ports to step off and explore.

Kotor cruise port is one of the most visually spectacular arrivals in the Adriatic. Ships sail through a deep fjord-like bay (Boka Kotorska) surrounded by limestone mountains that rise steeply from the water, with the walled medieval town of Kotor tucked at the base.

Split cruise port is the main gateway to central Dalmatia and one of the most remarkable cities in Croatia. The city is built around and inside Diocletian's Palace, a 1,700-year-old Roman fortress that the emperor built as his retirement residence around 300 AD.