Maui, both second youngest and second largest of the Hawaiian Islands, is home to the world's largest dormant volcano, Haleakala, meaning "House of the Sun." Last erupting about 200 years ago, it makes up the eastern end of the island. Maui was formed by volcanic activity from Haleakala on the east and the West Maui Mountains to the west. The connecting isthmus between the two spots was formed from joining lava from both and gives Maui its nickname, the Valley Isle.

Fitzroy Island sits off the coast from Cairns in Queensland, Australia, rising from the Coral Sea with rainforest and beaches that draw visitors year-round. A short, scenic ferry ride from Cairns’ marlin marina brings visitors to this tropical island, part of the Fitzroy Island National Park where rainforest meets reef.

Grenoble sits at the meeting point of three Alpine mountain ranges in southeastern France, giving it a setting that feels both dramatic and lived-in. With origins dating back to Roman times, the city has long been a crossroads of trade, science, and political thought.

Niagara Falls, New York, is home to one of the most powerful natural spectacles in North America. More than 3,000 tons of water pour over the edge every second, creating a thunderous roar and a rising mist that can be felt from blocks away. Visitors can stand just feet from the American Falls at Prospect Point or take the iconic Maid of the Mist boat tour, which has operated since 1846 and now features all-electric vessels.

St. Louis is a major city in the state of Missouri, United States, located along the western bank of the Mississippi River. It is widely recognized for the Gateway Arch, which defines its skyline and reflects its historical role as a point of movement toward the western parts of the country.