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.

Nestled along the south bank of the Danube, this historical Austrian city bursts with charm. A favorite stop on European river cruises, the city's most famous attraction is Melk Abbey, which dates back to the 11th century. The original Benedictine structure was lost to fires and foreign invasion, then rebuilt during the 18th century in lavish Baroque style, including a library and inner church covered in magnificent frescoes and gilded fixtures.

Ancient history comes alive in Athens, the capital of Greece. Gaze in wonder at the Acropolis and its iconic crown, the Parthenon. Take a deeper dive into the past and visit both the Acropolis Museum and the National Archaeological Museum, which house fascinating artifacts from this ancient city.

Marseilles is an enticing port city known for its delectable seafood, breathtaking views of the Mediterranean, and diverse melting pot of cultures.

Located on the coast of Sinaloa, Mexico, Mazatlán is a trendy resort town with spectacular beaches and thrilling nightlife. Centro Histórico (Old Town) and Plazuela Machado are replete with colorful, newly-restored neoclassical buildings.

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