From grand castles to resplendent cathedrals, Tallinn’s Old Town neighborhood, a UNESCO World Heritage Site, is the perfect place to begin exploring. Enter through Viru Väravad, or Viru Gate, the former fortress whose remaining two towers beckon you into the heart of the city.

Midway between Salzburg and Vienna, Linz boasts beautiful Baroque buildings, including Old Town Hall and the Old Cathedral, Alter Dom.

As a city located in a Baltic Sea archipelago, it's not surprising that Stockholm has 50 bridges and sightseeing boats moving people between its 14 islands. This contemporary and welcoming capital of Sweden is nonetheless easily navigable by foot. Every district here has a distinct flavor, from the sophisticated Östermalm to the bustling downtown energy of Norrmalm to the delightful Old Town.

Seven miles outside of historic Athens, the Greek coastal city of Piraeus lies upon the sparkling waters of the Aegean Sea and is the largest passenger port in Europe, servicing nearly 20 million passengers per year.

The "Big Easy" invites all to eat, drink and be merry, especially during Mardi Gras, its famous late-winter bacchanal.