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.

Kalmar Union, combination of the crowns of Denmark, Sweden, and Norway, effected at Kalmar, Sweden, by Margaret I in 1397. Because all three crowns were elective, the union could not be maintained by inheritance. Margaret's successors controlled Sweden intermittently until Gustavus I of Sweden dissolved the union (1523). Norway became independent in 1814.

Set on the Adriatic Sea, Zadar, Croatia, is a major Dalmatia historical center and a tourism magnet. Walk ancient streets, see Roman ruins and enjoy white-sand beaches.

Willemstad, the capital of Curaçao, is unlike any other city in the Caribbean. With its pastel-colored buildings lining the waterfront and a layout shaped by Dutch colonial planning, the city blends European design with Caribbean culture. Its historic center, divided by Sint Anna Bay into Punda and Otrobanda, has been recognized as a UNESCO World Heritage Site.

The Temple of Horus at Edfu has a massive entrance pylon covered with sunk relief carvings. This Ptolemaic temple was constructed between 237 and 57 B.C.E.

Yangshuo lies along the Li River in southern China’s Guangxi region, long known for landscapes that have shaped Chinese art and poetry for centuries.