Glacier Bay’s untouched beauty will astound you. A National Park and Preserve, as well as a UNESCO World Heritage site, it is covered with stunning tidewater glaciers and a variety of native flora and fauna. Be on the lookout for the variety of eye-catching wildlife, including eagles, moose, and humpback whales, who have made Glacier Bay home.

Batu Caves is a limestone hill and Hindu religious complex in Gombak, Selangor, just north of Kuala Lumpur. The site consists of several caves and caverns formed within a limestone outcrop, with the main Temple Cave reached by a staircase of 272 steps.

Lifou is the largest of the Loyalty Islands of New Caledonia and is known for its raised coral landscape, clear lagoons, and forested interior. Unlike Grande Terre, Lifou has no high mountain range, but its limestone plateau reaches enough elevation to create cliffs, caves, and elevated coastal viewpoints.

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.

Kolmanskop is an abandoned diamond-mining settlement in the Namib Desert, a short distance inland from the coastal town of Lüderitz in southern Namibia. The former settlement is surrounded by an exceptionally dry landscape of sand, gravel, and sparse desert vegetation. Today, windblown sand fills many of its empty buildings, creating a distinctive scene where rooms, corridors, and staircases are gradually being reclaimed by the desert.