Capri, a jewel of the Tyrrhenian Sea, has long been a favorite retreat for emperors, artists, and writers. This enchanting island off Italy's Amalfi Coast captivates with its dramatic cliffs, turquoise waters, and timeless elegance. The most iconic sight on Capri is the Blue Grotto, a sea cave illuminated by a magical blue light created by sunlight passing through an underwater cavity.

Freiburg was founded by the Dukes of Zähringen in 1120, and the layout of streets and squares of the rapidly prospering metropolis is still impressively reflected in today's cityscape.

The dazzling capital of the Czech Republic, the explorable Prague has fittingly been nicknamed "the City of a Hundred Spires." Halved by the Vltava River and notable for architecture Baroque, Renaissance, and Gothic, visitors will find much to take in here.

Sweden is a country where medieval towns, coastal archipelagos, and expansive forests sit side by side with modern design and a strong cultural identity. Stockholm, the capital, is built across 14 islands connected by bridges and ferries. The historic district of Gamla Stan features narrow, cobbled streets and colorful buildings dating back to the 13th century.

Whether cruising along its waters, exploring historic towns, or simply soaking in the scenic views, the Rhine River offers an experience that is as diverse as the countries it passes through.