Dominica, known as the “Nature Island of the Caribbean,” is a haven for eco-tourists and adventure seekers. Nestled between the French islands of Guadeloupe and Martinique, this lush island boasts a remarkable landscape of volcanic mountains, dense rainforests, and stunning waterfalls. Dominica’s most iconic natural wonder is the Boiling Lake, the second-largest hot spring in the world.

Douiret is a historic Berber village in southern Tunisia, set high among the rocky mountains and desert plateaus of the Tataouine region. The settlement is built along a steep mountain ridge, where old stone structures and partially abandoned homes blend into the surrounding rock. Douiret is best known for its traditional ksar, a fortified complex that once provided communal storage for agricultural harvests.

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.

The Great Barrier Reef stretches along Australia’s northeast coast, forming the largest coral reef system on Earth and one of the planet’s most complex living ecosystems.

The Kanmon Straits are a narrow waterway in Japan that separates the island of Honshu from Kyushu and connects the Sea of Japan with the Seto Inland Sea.