Hidden in the northern region of Costa Rica, the Celeste River (Río Celeste) winds through Tenorio Volcano National Park with a color so vivid it seems unreal. The river’s striking turquoise hue is caused by a natural chemical reaction between two mineral-rich streams, Quebrada Agria and Río Buena Vista, which merge at a point known as "El Teñidero." This one-of-a-kind phenomenon creates the illusion that the water has been dyed blue, even though no pigments are present.

The capital of Crete, Heraklion is a Greek port city and a popular stop on Mediterranean and Greek cruises. The city is an historical marvel, replete with archaeological wonders and remnants of the region's past. Highlights include the Heraklion Archaeological Museum, the Rocca a Mare Fortress, the Venetian Loggia, and just past the city limits, the Palace of Knossos.

Xi’an, located in central China’s Shaanxi Province, served as the starting point of the ancient Silk Road and was the capital of 13 imperial dynasties. Its long history is most famously represented by the Terracotta Army, an underground army of life-sized warriors discovered in 1974. Each figure has distinct facial features, hairstyles, and armor, designed to protect Emperor Qin Shi Huang in the afterlife.

Mogadishu, the capital of Somalia, is a city with a story that spans more than a thousand years. Its coastal setting has long shaped its character, blending African, Arab, and Persian influences that can still be seen in its culture and architecture today.

The Cook Islands, a group of 15 islands scattered across the South Pacific, offer a rare blend of Polynesian tradition and laid-back island charm. Rarotonga, the largest and most visited island, is ringed by a turquoise lagoon and backed by lush mountains. Visitors can circle the entire island in under an hour, stopping along the way for fresh coconut, beachside cafés, or a quick swim in the clear lagoon.