Berlin is an edgy city, from its fashion to its architecture to its charged political history. The Berlin Wall is a sobering reminder of the hyper-charged postwar atmosphere, and yet the graffiti art that now covers its remnants has become symbolic of social progress. Check out the Weltzeituhr (world time) Clock, topped by a model of the solar system, then turn back time by dining at the historic Zur Letzten Instanz, a 16th century restaurant that was frequented by Napoleon and Beethoven.

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.

Over the centuries, many cultures have added their mark to this prized piece of land. Today, you can experience those influences firsthand by exploring Istanbul’s mahalles (neighborhoods). From the holy sites of Sultanahmet and the 19th-century European elegance of Beyoğlu to the high fashion of Nişantaşı, the vibrant café society of Kadıköy and the football-loving streets of Beşiktaş, it’s easy to see why travelers say that Istanbul isn’t just one city, but many cities within one.

This city, full of colorful homes, canals and bridges, is one of Europe's most picturesque capitals. Must-sees on any visitor's itinerary include the Anne Frank House, the Van Gogh Museum and the world's only floating flower market. Rent a bike and join thousands of locals navigating Amsterdam's labyrinthine streets, or just take in the sights on foot. For an unusual and memorable alternative to hotels, consider staying in a houseboat.

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.

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.

Edinburgh is Scotland’s capital city, renowned for its heritage, culture and festivals. Take a long walk around the centre to explore the World Heritage Sites of the Old Town and New Town, as well as all the area’s museums and galleries. Then stop for a delicious meal made from fresh Scottish produce before heading out to take in one of Edinburgh’s many events — including the famous summer festivals of culture, or the Winter Festivals of music, light and ceilidhs.

The museums of Lisbon celebrate the rich history and culture of this Portuguese capital city. The Maritime Museum is perfect for kids (and grown-ups!) who adore all things nautical, while the Casa-Museu Dr. Anastácio Gonçalves is a hidden gem of colorful artwork. To fully appreciate the city’s dramatic stone architecture you can take a guided walking tour, or customize your own tour, making sure to visit the Padrao dos Descobrimentos, the Mosteiro dos Jeronimos, and the UNESCO World Heritage site the Torre de Belem.

New Delhi is all at once chaotic and calm, a complicated city where cows often wander the shanty-lined streets. The 17th century Red Fort is a mass of domes and turrets, while Chandni Chowk is an exercise in friendly haggling. Jantar Mantar features larger-than-life sundials and astronomical instruments that are still used to predict the weather. Travelers and locals flock to the India Gate, the national monument of India that honors the soldiers who died in World War I and the Third Afghan War.

Welcome to a capital city whose story goes back at least 3000 years. In Beijing, you'll find a wealth of history, both ancient (the Hall of Preserving Harmony, Summer Palace, Forbidden City) and more recent (Chairman Mao Memorial Hall, Tiananmen Square). For the best market experience, choose the Dirt Market over the touristy Silk Market. A visit to the Great Wall, the longest manmade structure in the world, is absolutely essential.