The best times to visit the world's most popular destinations

The Seven Wonders of the World earned the title for being among the most spectacular creations. They can take your breath away for their majesty — and be absolutely miserable for the sheer number of crowds. Their fame is most of the problem; too many people want to see the most celebrated sites on the planet, resulting in crowds, congestion and eye-popping costs.

The same is true for the world’s marquee travel destinations. The more famous and popular is, the worse the experience visiting — at least if you go during its high-season.

To avoid expensive disappointment, you could forgo such places entirely, heading off the beaten path or to “second cities.” Or visit when the bulk of the crowds have dispersed.

We talked to experts for the perfect combo of good weather, fewer people and affordable prices in some of the world’s busiest destinations.

Rome: February to March

It’s hard to appreciate a perfect scoop of gelato when you’re standing elbow to elbow to eat it, so skip Rome in the summer. “The summer has gotten really hot and crowded,” says Simone Amorico, CEO of Access Italy, a private tour operator.

Instead, he recommends visiting the Eternal City in either the winter — outside of the frenetic “festive season” just before Christmas to New Year — or spring. “Then it becomes quite busy after Easter,” Amorico said. According to Skyscanner, you’ll find the lowest airfare in the heart of spring between March and April.

Istanbul: September

Last year, Istanbul was ranked the most visited city in the world with 20 million international visitors, according to the annual index from Euromonitor International, a global research company. Most travelers head to Turkey between June and August, which is why local journalist Jennifer Hattam — who wrote our guide to Istanbul — recommends waiting until September.

“It’s really quite perfect,” she said. “You can still have the lovely weather when you’re on the ferry, or sitting outside for dinner and drinks.”

Hattam says the city is still bustling with activities, from art events to outdoor concerts. It’s a warmer and livelier time to go than her second choice: spring. According to Skyscanner, March is the cheapest time to fly to Istanbul from the United States, but September averages aren’t much higher.

Mexico City: June to September

Mexico City’s high season begins around the end of October — corresponding with Day of the Dead — through March, according to Anais Martinez, a food blogger and culinary tour guide from the city. But come June, the city starts to empty out with visitors wary of Mexico City’s rainy season, which runs through September. “Almost no one’s here, so you’re not going to bump into a bunch of tourists everywhere,” Martinez said.

Given the scorching temperatures during recent summers in North America, “they think that it’s too hot or that it will rain all day long,” Martinez said. Use that misconception to your advantage, and visit during the summer. While you can expect some rain, “it pours for forty five minutes, then it’s back to normal,” she said.

Paris: February to April

You’ve mapped out a quintessential Parisian sidewalk cafe. You’ve grabbed a table with a view of the Seine. Your server brings you a café au lait and pain au chocolate. It’s about to be the best morning of your life until you realize everyone around you is American. Sacre bleu.

To dodge the lion’s share of tourists who flock to Paris, avoid June through August, as well as late December. Instead, pack some layers and put February through April and November on your radar. It’s when hotel and flight prices are at their lowest.

Tokyo: April to May

When the trees of Japan are their most stunning, so is the price tag for a trip. Cherry blossom season, peak fall foliage, plus summer vacation are the most difficult time to get hotel rooms, train tickets and notable restaurant reservations. A better window to visit is February, says Yukari Sakamoto, author of Food Sake Tokyo.

Just before the sakuras arrive, it’s warm enough to walk around but not as crowded, and the ume plum trees are starting to blossom, she said. Average flight prices in February are about $100 more than when they’re at their cheapest in April to May.

Marrakesh: September or March

To find a happy medium between the lowest hotel and flight prices in Marrakesh, consider September for your trip. With summer’s intense heat abated, you can expect average temperatures to range from the 60s to 90s.

For the cheapest airfare alone, however, look for a March trip just before spring high season begins.

Las Vegas: January to April

There are a handful of event land mines to watch out for when planning a trip to Las Vegas: big conventions, bigger sporting events, some holidays and summer heat. No surprise here: the city saw record rates for hotel rooms for Super Bowl 58.

Pending there are no mega-events in town the week you’re planning your trip, January is the cheapest month for hotels in Las Vegas. But watch out for the Consumer Electronic Show early in the month, which brought about 130,000 attendees this year.

Barcelona: June

Summer may be the most popular time to visit Barcelona, but you don’t have avoid it altogether, says husband and wife photographers Majo Aguirre and Xavi Cano. Skip July and August when everyone’s on holiday and an influx of visitors descend from cruise ships, but June can still be enjoyable so long as you avoid staying near particular areas and sites (La Rambla, Sagrada Família). Flight prices are cheaper in June than they are in July or August, but you’ll find better deals if you travel in April, May or October, when you can expect some rain.