Krabi, located on the southwest coast of Thailand, is known for its towering limestone cliffs, warm Andaman waters, and a coastline dotted with over 150 islands. One of its most iconic sites is Railay Beach, which is accessible only by boat due to the cliffs that cut it off from the mainland. Railay is famous among rock climbers for its natural limestone formations, some of which hang directly over the sea.

Aegina, one of the Saronic Islands of Greece, is a short ferry ride from Athens yet feels far removed from the capital’s energy. Known since antiquity as a thriving maritime and cultural center, the island still preserves echoes of its past in archaeological sites and traditional villages.

Nafplion, a picturesque coastal town in the Peloponnese, is often hailed as one of Greece's most charming and romantic destinations. As the first capital of modern Greece, Nafplion boasts a rich history, evident in its well-preserved neoclassical buildings, Venetian fortresses, and Ottoman influences.

Coursing through 10 countries, the Danube is the second-longest river in Europe. This waterway, lined with fortresses and castles, rises in Germany's Black Forest and runs for 1,770 miles to the Black Sea. The Danube is an essential commercial thoroughfare for central and southeastern Europe, and several river cruise companies sail vessels on it year-round. Destinations along this river include Vienna, Budapest, Passau and Bratislava.

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.