Guadeloupe's major center is Pointe-à-Pitre, a conglomeration of old and new buildings clustered around the bustling harborside market. Pointe-a-Pitre is Gudeloupe's most popular city--explore the beaches of Grand-Terre and the French fort ruins and volcanic mountaintop of Basse-Terre.

Seclusion is the name of the game on Lizard. It's a large national-park island and surrounded by Osprey Island, Seabird Islet, South and Palfrey islands. Lizard has special historical interest due to Captain Cook's visit. It also has fine diving and fishing possibilities, 23 superb beaches (among the reef's best) and great swimming and snorkelling.

Ol Doinyo Lengai, often called the "Mountain of God," is an active volcano located in northern Tanzania and is a must-visit for adventurous travelers. Towering over the Great Rift Valley, this majestic peak is unique due to its lava composition. Unlike most volcanoes that produce molten lava, Ol Doinyo Lengai emits natrocarbonatite lava, which is unusually cool and flows like water. This rare phenomenon makes it one of the most intriguing volcanic landscapes on Earth.

If you find yourself in Rotterdam, there's a strong chance you've arrived by water. This popular port city (the second largest in the Netherlands) has gone through an architectural renaissance since World War II, with daring, innovative structures dotting the city (cube houses!) and defining its skyline. Café culture is on the rise here, so grab yourself a table and a cup.

Hol Chan Marine Reserve lies off the southern coast of Ambergris Caye, near San Pedro in northern Belize. The protected area covers coral reefs, seagrass beds, mangroves, and channels that form part of the Belize Barrier Reef. Its name comes from the Maya words for “little channel,” referring to a natural break in the reef that allows water to move between the Caribbean Sea and the shallow lagoon.