Caminha sits at Portugal’s northern edge, where the Minho River meets the Atlantic and marks the border with Spain. Its history is closely tied to defense and trade, visible in remnants of medieval walls and a compact historic center that once guarded the river mouth.

Long regarded as one of the freest-thinking college towns in the U.S., Ann Arbor is home to the University of Michigan, the Gerald R. Ford Presidential Library and Domino's Pizza. While you're in Ann Arbor, be certain to see the city's many fascinating historic buildings; the Kelsey Museum of Ancient and Medieval Archaeology; and Kerrytown (a diversity of specialty shops and eateries in restored 19th-century buildings close to the Farmers Market).

Rio Dulce is a river region in eastern Guatemala that connects Lake Izabal to the Caribbean Sea. The area is centered around the town of Fronteras and the long waterway that cuts through tropical forest, limestone cliffs, and wetland habitats.

Montecatini Terme, in Tuscany’s Valdinievole region, is one of Italy’s most renowned spa towns, celebrated for its thermal waters and elegant Belle Époque charm.

Galle, a coastal city in southern Sri Lanka, is a place where history and the sea are inseparably linked. Once a vital port on the spice trade routes, Galle reached its peak under Dutch colonial rule in the 17th century, when the massive Galle Fort was built.