Barranquilla sits near the mouth of the Magdalena River on Columbia's Caribbean side. It is a major seaport and a center of commerce, but everyone breaks loose for four days in February for one of the liveliest carnivals outside of Rio.

Greece’s southern coastline is home to Gythion, a historic port town nestled in the Peloponnese region. Once the naval base of ancient Sparta, Gythion has played a key role in maritime history for centuries. Today, its harbor is lined with colorful neoclassical buildings and fishing boats, creating a picture of daily life that remains connected to its seafaring roots. Just offshore lies Cranae Island, linked to the mainland by a stone causeway.

Plovdiv, one of the oldest continuously inhabited cities in Europe, carries over 8,000 years of history layered into its streets. The Roman Theater, still in use today, was discovered by accident in the 1970s and now hosts operas and concerts overlooking the Rhodope Mountains. Nearby, visitors can walk the remains of a Roman stadium buried beneath the main pedestrian street, where modern shops and cafés stand above ancient foundations.

Puerto Madryn is a seaside city on the eastern coast of Argentina. Facing Golfo Nuevo and the South Atlantic Ocean, this coastal destination is popular for its beaches, marine life, nature preserves, and Patagonian museums.

As a city located in a Baltic Sea archipelago, it's not surprising that Stockholm has 50 bridges and sightseeing boats moving people between its 14 islands. This contemporary and welcoming capital of Sweden is nonetheless easily navigable by foot. Every district here has a distinct flavor, from the sophisticated Östermalm to the bustling downtown energy of Norrmalm to the delightful Old Town.