Why it's great for kids: Consider London a smart entry-level foreign travel experience. There's no language barrier, the food is kid-friendly (those chips!), and there's lots to do around one of the major characters of modern childhood -- Harry Potter.
Put it on your itinerary: Harry Potter fans can get their Platform 9¾ photo op at Kings Cross station, then head out for the fabulous Harry Potter studio tour just outside the city, where you can see costumes, props, and sets from the movies. Theater-loving families can take in some of London's finest at the West End, or step back in time with a Shakespearean performance at the gorgeous replica of Shakespeare's own Globe Theatre. Touring the Tower of London gives you a taste of old English history in all its dark and dramatic glory, including a look at the royals' jewels and old weaponry. The London Eye lets guests get grand views of England from atop the mammoth Ferris wheel.
Why it's great for kids: Ooh-la-la! Far from being snooty, the French capital offers plenty of fun for families, from kid-friendly cooking classes to sweet playgrounds tucked throughout the city. And if you convince your kids that Remy from Ratatouille works the kitchen at that fancy restaurant you splurge on -- we won't tell a soul.
Put it on your itinerary: The Eiffel Tower is an obvious must (take the stairs to avoid the line and let your kids burn off some energy on their way up), along with the city's other iconic pieces of architecture, the Arc de Triomphe and Notre Dame Cathedral. A tour of the cool and slightly creepy Catacombs beneath the city is perfect for your gothic tween. Take a break at one of Paris's lovely playgrounds -- the Luxembourg Gardens are a special favorite, offering wooden boats that kids can sail on placid ponds, a charming carousel, puppet shows, and more. And make sure you head to the Louvre, of course, for a look at some of the masters.
Why it's great for kids: Our friendly Canadian neighbors give us a little bit of French flair, minus the transcontinental flight.
Put it on your itinerary: Give your kids a sense of the city's past with a stroll through Old Montreal, then visit Pointe-à-Callière, a museum of local archaeology and history. Mont-Royal, the mountain in the center of the city, offers family-friendly activities galore, including hiking and paddle boating on Beaver Lake. Or head to the Montreal Biodome, where you can immerse yourself in four different ecosystems, complete with temperature shifts, plants and animals -- from tropical forests filled with monkeys to polar ecosystems with lovable penguins. (Afterward, head to the top of the Tour de Montreal, the world's tallest leaning tower.) Winter can be a wonderful time to visit, with the grand Hôtel de Glace (ice hotel) that's created each winter, and ice skating at several locations throughout the city, including the charming Patinoire du Bassin Bonsecours outdoor rink in Old Montreal.
Why it's great for kids: The land Down Under offers exotic animals, amazing culture, and lots of activities to keep the little ones occupied -- and no translators required. Bonus: Finding Nemo fans will remember that key parts of that Pixar adventure took place in Sydney Harbour and at the (sadly) fictional 42 Wallaby Way in Sydney.
Put it on your itinerary: Sydney's iconic Opera House is a must-see, and often features shows and programs geared to younger guests (even toddlers!). Thanks to Sydney's coastal location, there's a slew of terrific family-friendly beaches, which feature playgrounds for a little out-of-the-water fun. See what lurks below the waves with a visit to Sydney Aquarium, home to more than 12,000 marine animals, including dugongs (sea cows). And there are a ton of ways to see Sydney's sights, whether you and your family venture up to walk across the Sydney Harbour Bridge, or Skywalk on a glass-floored platform above the city.
Why it's great for kids: You'll get the best of both worlds -- a bustling city culture and a beach vacation.
Put it on your itinerary: Parque de Palapas, the city's central park, offers food carts, performances, and the kiddo essential, playgrounds. Mercado 28 is a bustling marketplace where you and the kids can bargain for local treasures to bring home. Isla de Mujeres lets you get away from the city's hustle and bustle with a trip out to this laid-back island just off the coast -- the Garrafon Reef Park there lets you swim with dolphins or stingrays or take a ride on a zip line. When you're not busy lazing on the beach, make sure you head out to tour Chichén Itzá, the Mayan Ruins nearby.
Why it's great for kids: Denmark's capital is literally a fairy-tale city -- it's where Hans Christian Andersen wove his classics, like The Little Mermaid. And if your kids are even mildly Lego-obsessed, they'll probably be thrilled at a chance to visit the country where the blocks were first created.
Put it on your itinerary: You'll want to visit Tivoli Gardens, the scenic amusement park at the heart of the city, with gorgeous gardens and architecture and one of the world's oldest still-in-use wooden roller coasters. Or head out to the 432-yer-old Bakken, the world's oldest amusement park, which has thrill rides for kids and plenty of places to picnic. Join the Danish masses and bike around town to see the sights. You can check out the Little Mermaid statue in the harbor, or tour the Rosenbourg Castle for a look at 400 years of royal Danish history. And of course, Legoland is probably a must-do.
Why it's great for kids: Tokyo's high price tag and faraway location may make it a once-in-a-lifetime travel option, for sure, but it's worth the splurge. While Japanese is the official language, you'll find many English speakers, making it surprisingly easy to get around with a little help from friendly locals.
Put it on your itinerary: If your kids love manga, stop in at Studio Ghibli, where Japanese animator Hayao Miyazaki made his famous movies like Spirited Away. (Even if your kiddos haven't seen the films, they'll love the interactive exhibits.) Budding fashionistas will definitely want to head to the Harajuku neighborhood for style inspiration (and maybe buy a few accessories to add flair to their own attire). Don't leave without touring the Imperial Palace, with its grand buildings and gardens, and maybe taking in a local sumo tournament (they take place in odd-numbered months). And if your kids were pining for a theme park vacay, you can always head to Tokyo Disneyland!
Why it's great for kids: Even the pickiest eaters generally like Italian cuisine -- and pizza, pasta, and gelato are in no short supply here. Kids who are into history and the arts will find something to love around every corner.
Put it on your itinerary: Make lots of time for art -- the works of masters like Leonardo da Vinci and Michelangelo are scattered throughout the city, in both museums and the grand cathedrals (the Vatican's Sistine Chapel should also be on your must-visit list). Showcase Rome's grand past with visits to the Forum and the Colosseum (essential for any little sports fans) and the Pantheon. Then take a break from all that culture by letting kids burn off steam running around one of the piazzas scattered around town.
Why it's great for kids: Don't fret about Amsterdam's Red Light District -- this charming Dutch capital is one of the most family-friendly international cities around. And tween and teen fans of The Fault in Our Stars will jump at the opportunity to follow in Gus and Hazel's footsteps.
Put it on your itinerary: Make (lots of) time to play in Amsterdam's legendary playgrounds: There's one in every neighborhood and they often have different themes or activities -- including some with petting zoos. A cruise lets you get a look at Amsterdam's legendary canals without too much walking. The Van Gogh Museum is a vital stop for art lovers, and the Anne Frank House offers a glimpse at the famous author's life in hiding. (It's also a key locale in The Fault in Our Stars.) Kids age 4 and up can enjoy Ondekhoek (Discovery Corner), a cool science center filled with experiments they can do on their own -- while you and your mate enjoy a little quiet conversation.
Why it's great for kids: This South African capital can be a family-friendly outpost for a safari excursion, or a destination in its own right.
Put it on your itinerary: Take the cable car up to the top of Table Mountain, where you can enjoy hiking trails and amazing views of the ocean and mountains from its flat top. Boulders Beach offers a chance to kayak out to see penguins in the wild, and you can take surfing lessons at nearby Muizenberg. Spier's Cheetah and Raptor Center lets kids get up close and personal with some of the more magnificent (and dangerous) animals in Africa. Get a sense of Cape Town's local history with a tour of one of the townships by Uthando Tours, which allows your family to get involved with the philanthropic programs -- community gardens, children's music and dance groups, and more -- that you visit during the tour.