Maybe you saw it coming and hoped for the best—or maybe you totally missed the warning signs. Either way, it’s too late now. The travel honeymoon has ended jarringly, leaving you with an empty feeling in the pit of your stomach: You’ve just been scammed.

When traveling, you (and your money) can be easy targets for scammers, especially if you’re in a totally foreign place or don’t speak the language. So, it’s important to learn what to watch out for. Here are four of the most common global scams, and what you need to know to avoid them.

Avoid Taxi Trauma

Taxi drivers around the world can smell fresh meat. You step out of the airport, wide-eyed and excited, only to be swarmed by hundreds of people shouting, “Taxi! Miss? Taxi! Where you want to go?”

Make eye contact, and one of them may grab your bag to ensure you are a customer. Once you get in, the driver will insist on taking you to his uncle’s carpet shop, recommend a hotel (read: refuse to drop you off anywhere else), and charge you an astronomical taxi fare. Demand a meter, and you may notice the numbers jumping by the second. And if you confront the driver (especially if the meter is rigged) you may be dealing with the taxi mafia and find yourself in a dangerous spot.

How are you supposed to deal? Keep in mind the two most important words in the taxi game: reputable and regulated. Before you travel somewhere new, research the best taxi companies and the standard pricing on trusted travel forums (for example, in Hanoi, there are four reputable taxi companies that don’t rig the meters—look them up here). Double check fares for common routes with the locals when you arrive, and learn how to ask to be taken somewhere in the local language. And don’t ever get in unmarked cabs or go with a stranger offering you a ride.

Don’t be Mesmerized by Shiny Things (Even with “Certificates”)

If you find yourself in a gem or jewelry shop in a tourist area, no matter how pretty things look, don’t buy anything and expect it to be genuine—even if the bauble comes with a certificate of authenticity and other travelers guarantee the piece is worth double its price (they’re likely in on the scam too). Most of these sorts of gem shops actually hawk nothing better than creatively cut glass at extreme prices to unsuspecting travelers who think they’re getting great deals.

In fact, avoid gem shops, carpet shops, “uncle” shops, and any other shop that tries to lure you to come in at all costs. These are usually elaborate fronts for selling fake goods, ripping people off, or selling items at five times their price. Even if you report these places for their scams, don’t expect much—they’re often already well-known for their dishonesty. You won’t get your money back (though you may get a look of pity or some laughter for your mistake). The legitimate jewelry shops are typically big and famous and will be frequented by the locals. They’ll offer you fair and fixed prices, not “amazing” deals.

Dodge Dodgy Tour Operators

“Get us our things, or we’re going to call the Embassy!” we screamed at one point, during what was turning into the worst tour of our lives. A typhoon was coming into Halong Bay, and we couldn’t get back into our boat. What was supposed to be a day trip turned into two days stuck on a tourist ghetto island, while fighting to get back our possessions that had been left on the boat after our tour company faked a bus breakdown. Eventually, we had to report the company to the tourism authority, and then to the police.

This was pretty much the worst-case scenario, but tour operators have been known to run sham tours. One in particular to be cautious of is any excursion involving monkeys. Many tourists think seeing a temple or an island full of the primates will be cute, but tour operators can charge exorbitant amounts, only to take you to a tourist trap filled with hundreds of thieving (not adorable) monkeys.

So, make sure you do your research before you go, and find responsible tour operators. Get the opinion of the locals, read up on travel forums, and query others who have already been on the excursion you’re interested in. And remember that expensive doesn’t always mean better. I’ve had great experiences with small local companies, and hit or miss trips with major ones.

If a tour operator does try to pull one over on you, definitely report them to the local tourist authority. And do other travelers a favor by reviewing the experience on travel forums and websites.

Be Wary of Tall Tales

At a popular restaurant for aid workers on the Thai-Burma border, the waitresses always knew who was new in town. And they would tell them their stories, usually starting with something like “My brother is sick,” or “My house burned down.” Caring customers would, of course, want to help. Newcomers often forked out hundreds of U.S. dollars in support, only to find out two days later that the person they gave the money to had fled the country or purchased a new motorbike.

Stories are one of the best parts of traveling—but it’s important to learn how to discern the truth from the tales told to exploit your curiosity and generosity. Use your gut, fact-check with other friends and colleagues familiar with the area (was there really a big fire last week?), and search the Internet for some of the most common tall tales told to travelers.

Scams happen everywhere (even at home), but they can be harder to distinguish when you’re in an unfamiliar place. And while you shouldn’t be afraid of traveling to new places, you should be a smart tourist: Read up on where you’re going, talk to people who’ve been to your destination before, and learn as much as possible about what to look out for. Once you get there, be savvy and listen to your gut—if something doesn’t feel right, it’s probably not.

And if you do get overcharged—well, it happens to the best of us. I’m still making my morning chai with the cardamom a spice man in Kerala sold to me at quadruple the price. Sometimes, you just have to let it go and have a laugh.

Photo courtesy of Klaus Nahr.