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.

Shanghai is a city where contrasting timelines meet at every corner. Once a small fishing village along the Huangpu River, it grew rapidly during the 19th century into a major trading port. Today, its skyline tells a story of that transformation. On one side, the Bund’s colonial-era buildings stand tall in limestone and granite; on the other, the futuristic towers of Pudong, like the Shanghai Tower and Jin Mao, stretch into the clouds.

Amarante, located in Portugal’s northern region of Tâmega e Sousa, sits quietly along the banks of the Tâmega River, framed by stone bridges, historic churches, and lush hills. The city is best known for its connection to São Gonçalo, a 13th-century monk whose name now graces the arched bridge and the grand convent-church that stands beside it.

This pleasant port town provides a nice, calmer contrast to bustling Rome, so travelers are advised to not simply pass through, but linger and discover more of Civitavecchia. Explore Forte Michelangelo, shop at Corso Centocelle, see the neoclassical Trajan Theatre, and delve into the therapeutic Taurine Baths of Civitavecchia.

Salamanca, often called the “Golden City” for the warm glow of its sandstone buildings, is a place where centuries of stories are etched into every wall. Visit its historic center to wander through cobbled streets lined with architectural marvels. The University of Salamanca, founded in 1218, is one of the oldest in Europe and still buzzes with student life.