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.

Marathon, located near the center of the Florida Keys, is a vibrant island city known for its fishing, boating, and tropical charm. Nestled between Key Largo and Big Pine Key, Marathon is surrounded by clear waters, coral reefs, and sandy beaches, making it a prime destination for water-based recreation.

Boa Vista is an island in Cape Verde known for its broad sandy landscapes, volcanic terrain, and long Atlantic coastline. It is the easternmost of the Barlavento islands and has a relatively dry climate, with much of its interior covered by open plains, dunes, and rocky ground. Sal Rei, the island’s main town, sits beside a sheltered bay and serves as its principal commercial centre.

Lewiston and Clarkston are located at the confluence of the Snake and Clearwater Rivers at an elevation of 738 feet above sea level. The valley is rather narrow with a range of hills to the North sloping abruptly to about 2,000 feet above the valley floor.

Cooper Island is a small, rugged island off the southeastern coast of South Georgia, lying near the entrance to Drygalski Fjord. Its landscape combines steep rocky slopes, snowfields, glaciers, and sheltered coastal areas, with the island surrounded by cold waters often containing sea ice. The island is part of the protected South Georgia environment and is visited primarily for its wildlife and scenery. Expedition vessels may approach or land when conditions permit, although access depends on w