Oceania Sonata: 21-Night Transatlantic from Miami

Miami cruise port, officially called PortMiami, is the busiest cruise port in the world by passenger volume. Millions of people pass through here every year, and nearly every major cruise line uses it as a home port.

Santa Cruz de Tenerife is the capital of Tenerife, the largest of Spain's Canary Islands, located in the Atlantic Ocean about 300 km off the coast of Morocco. The cruise port sits in the heart of the city, directly adjacent to the commercial center and within walking distance of the main shopping street and waterfront.

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.

Valencia cruise port is Spain's third-largest cruise port (after Barcelona and Palma de Mallorca) and a rising star on Western Mediterranean itineraries. Valencia sits on the east coast of Spain about 350 kilometers south of Barcelona and 350 kilometers east of Madrid.

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.

Built on a narrow strip of land between the Mediterranean and the Etang de Thau lagoon, Sete is a working fishing port of about 45,000 people on the Languedoc coast. The city calls itself the Venice of Languedoc for its network of canals, though the comparison undersells what makes Sete different: this is a genuine fishing town where trawlers unload the catch at the port each morning and the restaurants cook what came in that day.

Marseille cruise port is France's busiest and one of the major stops on western Mediterranean itineraries. The city is France's second largest and its oldest, founded by Greek sailors over 2,600 years ago, and it has a rougher, more authentic edge than the polished Riviera towns further east.

Nice is the capital of the French Riviera, a Mediterranean city of about 340,000 people wedged between the Maritime Alps and the Cote d'Azur coastline. Cruise ships anchor in the bay at Villefranche-sur-Mer, a small harbor town about 6 km east of Nice, or occasionally dock at Nice's own port.

La Spezia is a working Italian naval and commercial city on the Ligurian coast, but cruise passengers know it primarily as the gateway to Cinque Terre, the five colorful fishing villages clinging to the cliffs along a rugged stretch of coastline just north of the city. The La Spezia cruise port sits at the edge of the city center, a short walk from the train station that connects directly to the Cinque Terre villages.

Florence (Livorno) cruise port is the main Tuscan stop on Mediterranean itineraries, but it's worth being clear about what you're actually docking at. The port is Livorno, a working industrial city on the Ligurian coast, about 85 kilometers west of Florence.