If you find yourself in Rotterdam, there's a strong chance you've arrived by water. This popular port city (the second largest in the Netherlands) has gone through an architectural renaissance since World War II, with daring, innovative structures dotting the city (cube houses!) and defining its skyline. Café culture is on the rise here, so grab yourself a table and a cup.

This cultural capital and university city holds more than 2,000 years of history and is the cultural hub of Germany. Marvel at the gorgeous twin-spired Cologne Cathedral, known for its gilded medieval reliquary and sweeping river views, or lose yourself in one of Colonge's many museums for a few hours. Cologne boasts of having most pubs per person in Germany, so make sure you sit down for a refreshing regional Kölsch beer during your travels!

Croatia, a gem of the Adriatic coast, invites travelers to explore its stunning landscapes and rich history. The capital city, Zagreb, is a vibrant blend of medieval charm and modern sophistication. Wander through the Upper Town (Gornji Grad), where cobblestone streets lead you to the historic Stone Gate and the majestic Zagreb Cathedral. For a taste of local culture, visit Dolac Market, where fresh produce and traditional Croatian delicacies create a lively atmosphere source.

Mount Kenya, the majestic volcanic mountain located in central Kenya, is a natural wonder that captivates visitors with its dramatic landscapes and rich biodiversity. As Africa's second-highest peak, standing at 5,199 meters (17,057 feet), Mount Kenya offers an array of trekking routes that lead adventurers through lush forests, alpine meadows, and glacial valleys.

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.