The old Burgundian university town of Leuven offers a range of adventures for overnight visitors or day-trippers from Bruges and Brussels. Tourists will find everything from gastronomic tours to architectural gems like the Gothic Town Hall. Nature lovers won’t be disappointed. The Kruidtuin Botanical Garden’s herbal gardens are the oldest in Belgium, and Heverleebos, a “city wood,” offers a respite for urban dwellers. The exploring is easy in Leuven, on foot or on one of the ubiquitous bikes.

Unassuming Brussels is the capital of Belgium, Flanders and Europe. Medieval Grand-Place, is indeed grand, with many 17th-century buildings and daily flower markets. Reopened in 2006, the Atomium, Brussels' Eiffel Tower, provides great views, inside and out. Architecture fans should visit Musee Horta, home of Belgian master architect Victor Horta. St. Gery's clubs and bars are packed year-round. Seafood eateries abound in Ste. Catherine. Walk, rather than get snarled up in traffic, in the narrow streets.

The picturesque town of Mechelen, a hidden Flemish gem, sits between Brussels and Antwerp. Students of the world-renowned Carillon bell-ringing school provide an atmospheric soundtrack for sipping coffee at a sidewalk café in one of the town's charming squares. Many pedestrian areas make this a delightful town to promenade about, admiring hundreds of listed buildings and monuments, many dating back to 16th century. Highlights include Gothic and Baroque churches and the famed St Rumbold's Tower.

Touching Belgium on its west and just a few miles from Germany to the east, Maastricht is the capital of Holland’s southernmost region, Limburg. A town rich in history and culture, Maastricht boasts two wonderful town squares: Vrijthof, with Sint-Servaas Church, Sint-Jan's Cathedral and many bars, cafes and restaurants; and Markt, home to the town hall and, on Wednesday and Friday mornings, a fantastic vendor market. The city’s Vestigingswerken, or old town fortifications, are another big draw.

Lively Antwerp is a hidden gem. Its medieval streets, Renaissance monuments and vibrant nightlife tend to be overshadowed by its reputation as center of the diamond trade and as the world's fifth-largest port. Biking is a popular choice for getting around this stylish Flemish city. See thousands of Old Masters at the Royal Museum and Rubens House. Experience the bustle of life at the Grote Markt. Marvel at the art and architecture of the still unfinished Cathedral of Our Lady, started in 1351.

Best known as the capital of Charlemagne's Frankish empire, today's Aachen sits at the juncture where Germany meets the Netherlands (the Dutch know it as Aken) and Belgium (where "Walloons" call it Aix-la-Chapelle). But Aachen's history goes back even further than 8th-century Charlemagne. Roman soldiers dating back to the 1st century AD cherished its hot springs (as did Charlemagne, who loved a good spa day just as much as the next guy). Aachen Cathedral, northern Europe's oldest and a UNESCO World Heritage Site, is the city's main attraction.

Belgium's fourth-largest - and most beautiful - city is home to a quarter of a million people and a flourishing flower export trade. An important port, Ghent's city center is a pedestrian area that is like a museum to early Flemish architecture and a testament to the city's medieval might. Impressive Gothic sites, such as dramatic St. Bavo's Cathedral and the Castle of the Counts, inspire awe. The works of Flemish masters are housed in the distinguished Museum voor Schone Kunst.

Lingering over pain au chocolat in a sidewalk café, relaxing after a day of strolling along the Seine and marveling at icons like the Eiffel Tower and the Arc de Triomphe… the perfect Paris experience combines leisure and liveliness with enough time to savor both an exquisite meal and exhibits at the Louvre. Awaken your spirit at Notre Dame, bargain hunt at the Marché aux Puces de Montreuil or for goodies at the Marché Biologique Raspail, then cap it all off with a risqué show at the Moulin Rouge.

From Shoreditch’s swaggering style to Camden’s punky vibe and chic Portobello Road, London is many worlds in one. The city’s energy means that no two days are the same. Explore royal or historic sites, tick off landmarks from your bucket list, eat and drink in exclusive Michelin-starred restaurants, enjoy a pint in a traditional pub, or get lost down winding cobbled streets and see what you stumble across – when it comes to London, the possibilities are endless.

In Vienna, the coffee house isn’t just a hangout: it’s an institution. Lingering over a newspaper with a pastry and a strong espresso drink is, according to UNESCO, officially a Viennese cultural pastime. Walk off your slice of Sachertorte with a self-guided tour of the city’s stunning traditional, Secessionist, and modern architecture, such as the Imperial Palace, the State Opera House, the Kirche am Steinhof, or the Kunsthistorisches Museum, an exercise in ornate geometry.

Barcelona feels a bit surreal – appropriate, since Salvador Dali spent time here and Spanish Catalan architect Antoni Gaudí designed several of the city’s buildings. Stepping into Gaudí’s Church of the Sacred Family is a bit like falling through the looking glass - a journey that you can continue with a visit to Park Güell. Sip sangria at a sidewalk café in Las Ramblas while watching flamboyant street performers, then create your own moveable feast by floating from tapas bar to tapas bar.

Rome wasn't built in a day--and you'll need much more than a day to take in this timeless city. The city is a real-life collage of piazzas, open-air markets, and astonishing historic sites. Toss a coin into the Trevi Fountain, contemplate the Colosseum and the Pantheon, and sample a perfect espresso or gelato before spending an afternoon shopping at the Campo de’Fiori or Via Veneto. Enjoy some of the most memorable meals of your life here, too, from fresh pasta to succulent fried artichokes or a tender oxtail stew.

One of Islam’s most holy cities, Medina, is a sprawl of minarets and shops wrapped around the landmark, the Prophet’s Mosque. Like the rest of central Medina, it’s for Muslims only and is surrounded by plenty of hotels and eateries to welcome the pilgrimage crowd.

The shining jewel of Qatar, Doha is a multicultural city, home to most of the country's population as well as expatriate communities from a range of origins. Shopping abounds in the city's plentiful malls, while the Corniche impresses visitors with picturesque architecture and dazzling views of the harbor. Doha boasts myriad cultural facilities, including the futuristic Education City and the National Museum.

Dubai is a destination that mixes modern culture with history, adventure with world-class shopping and entertainment. Catch a show at the Dubai Opera, see downtown from atop the Burj Khalifa and spend an afternoon along Dubai Creek exploring the gold, textile and spice souks. If you’re looking for thrills, you can float above the desert dunes in a hot air balloon, climb aboard a high-speed ride at IMG Worlds of Adventure or skydive over the Palm Jumeirah.

Conquering New York in one visit is impossible. Instead, hit the must-sees – the Empire State Building, the Statue of Liberty, Central Park, the Metropolitan Museum of Art – and then explore off the beaten path with visits to The Cloisters or one of the city’s libraries. Indulge in the bohemian shops of the West Village or the fine dining of the Upper West Side. The bustling marketplace inside of Grand Central Station gives you a literal taste of the best the city has to offer.

Known as the safari capital of Africa, Nairobi is an energetic, modern city that serves as a fascinating introduction to both wildlife and nightlife. Music clubs pulse with life, shops and markets bustle, and a mélange of restaurants will tempt your palate in this former Maasai watering hole. Top sights include the Karen Blixen Museum, Giraffe Centre and the black rhinos of Nairobi National Park. The compact city center is safe to walk in and taxis make other areas accessible.