Just about every blog touts solo travel as something you have to do at least once in your life. It’s lauded for the flexibility it gives adventurers, plus its opportunity to clear one’s head. To be fair, it can certainly be refreshing to follow your own itinerary.

But what about safety? Or costs? It can be equally refreshing to know someone has your back when you’re out late at night in a new destination and can split the fees on that ridiculously large hotel room (plus room service) you just had to have.

Navigating the “to solo” or “not to solo” question can be tricky. However, in some cases, there’s a lot more to it than just a table for one.

We uncovered spots that are so secretive they remain a mystery to all but a few people and others that require you to sign up with an official tour group filled with strangers to even step foot inside. There are additional locations that have risen in popularity to the point of facing restriction on the number of visitors allowed and others that have been forced to shut out tourists entirely. In these locations, you might be met with hostility as locals equate tourists with loud parties, litter, and vandalism.

Keep reading and travel at your own risk in places where tourism has gone from profitable to problematic. The penalty could be dirty looks, a fine, or much, much worse.

24 Take Your Trash And Get Out: Tourism Causing Pollution In The Great Barrier Reef

Australia’s pride and joy (as long as you don’t count koalas) is clearly the rich biodiversity of the Great Barrier Reef. It is one of the most popular spots in the world for divers, but is falling victim to its popularity.

While divers do undergo training before being unleashed to the depths, there’s not a lot of oversight to make sure they follow good diving practices once they are in the water. Divers that won’t be satisfied until they’ve seen the reef up close should make sure to avoid coming in contact with any of the corals and should, under no circumstances, leave anything in the water.

23 No Entry Permitted: Keep Your Distance From The Most Haunted Place In The World

If you’re looking to ramp up your Halloween-season fright activities, consider reading about Poveglia. A small Italian island, it is considered one of the most spooky locations in the entire world.

In its prime, the island served as a quarantine spot for those afflicted with the plague. More recently, it housed an asylum. Today, it is off-limits to residents and tourists, many of whom believe the ghost stories and wouldn’t dare go anyway.

The authorities have tried to sell the island in hopes it could be redeveloped into something useful, but so far there are no takers (so surprise there).

22 We're Not Wanted: The Locals Don’t Want You On Pig Beach

When we talk about the locals of pig beach, we really mean the pigs themselves. The pigs don’t want you there because you and others like you keep feeding them and making them sick.

Yes, they are extremely adorable and it is so fun to see the baby piglets rooting around in the sand and the larger ones heaving their potbellies into the water for a swim. However, they are also self-sustaining and don’t need your help (they also don’t need you to try riding them).

21 Don't Dare Go Alone: You Will Need To Hire A Guide To Enter Chernobyl

It seems like there is an application for everything nowadays: school, jobs, housing, pet adoption, etc. In the latest move, there’s now an application to visit Chernobyl. Yep, that Chernobyl. The site of the 1986 nuclear disaster.

With at least ten days advance notice to the Ukrainian government, it can be all yours. Your chances of getting in are higher if you apply with an official tour group, but still no guarantees. The site isn’t supposed to still be radioactive, though we recommend you read the fine print on the application for warnings.

20 Stay Away: Overcrowding Has Forced Maya Bay Beach To Close

Leonardo DiCaprio fans just had to get a glimpse of the beach that he made famous in his film “The Beach”. So much so, in fact, that Thailand has now been forced to close the beach altogether.

Tourism got so out of control there that people could hardly walk around (and they definitely couldn’t lay down to soak up the rays). The result was a closure and now nobody can enjoy the white sands while they daydream about Leo.

19 Not Allowed: A Copy Is The Closest You Will Get To Seeing Lascaux Caves

As far as replicas go, the one of the prehistoric paintings in Lascaux Cave is pretty good. Discovered in 1940 and accessible until 1963 when officials realized that oxygen was destroying the paintings, visitors could descend into the cave to get a sense of the animals that were living at that time depicted in the artwork.

The French government recently spent $64 million to make a copy so that people could still see the paintings without damaging them further. It took thirty-four artists three years to complete. 

18 Caution To Summer Tourists: Unless It’s Off-Peak, Don’t Go To Cinque Terre

We get it. The colorful buildings precariously clinging to a rocky cliff above pristine waters make for a perfect picture. That shot alone is worth the trip all the way to Cinque Terre on the Italian Riviera.

However, residents and the local government would prefer you just stare longingly at photos of the village on Instagram rather than visit. While tourists in the winter months do add to the economy, the hordes of tourists that line the streets during warmer weather do nothing but frustrate the locals.

17 The Big Freeze Out: You Won't Be Able To Get Close To This Big Ben

Covered in ice and located between Madagascar and Antarctica (but belonging to Australia), the majestic Big Ben dominates the Indian Ocean. As opposed to the clock tower in London, this Big Ben is an active volcano that could spew lava and ash at any time (and has on at least three occasions in the last two decades).

For this reason, visitors are not allowed onto Heard Island where it is found (though scientists can access a nearby island to study the volcano).

16 Take Your Party Elsewhere: AirBnB And Other Vacation Rentals Encouraging Party Scene In Amsterdam

Amsterdam has long had a reputation, but now it is officially becoming the party capital of Europe. Bachelorette parties, stag nights, and other general forms of group debauchery are putting a strain on the city center. The rise in vacation rentals like Airbnb simultaneously promotes the party scene (everyone can stay together for less money than the cost of a hotel), while also causing rents to skyrocket.

This has pushed locals out of their own neighborhoods and they’re not too keen on it.

15 You Can't Do It Alone: Climb To Great Heights With An Experienced Company At Mount Kilimanjaro

While restrictions are not nearly as strict as they are for Mount Everest (where you need to show a clean bill of health to obtain a permit), you’re still going to need to follow a few rules if you want to climb Mount Kilimanjaro.

To start, you should probably be in decent physical shape. Secondly, you must hire a guide. Solo climbers are not allowed to scale the mountain (all 19,341 feet of it), no matter how good they think they are.

14 Keep Out: Litter Is Destroying Boracay Island In The Philippines

After six months of intense cleanup, the garbage has been cleared and Boracay Island is once again open for tourism as of this week. However, beach-goers that previously visited are going to see some new rules in place.

For example, anyone visiting must present confirmation of their stay at an accredited hotel. Also no sandcastles, no barbeques, and no pets. The reopening is just a trial run as the President has already stated that he has no problem shutting it down again if the rules cannot be followed.

13 Watch Your Back: Scientists Only Protocol At Snake Island

If snakes are your biggest fear, just skip over this entry so you don’t pass out. Are you gone? Okay, everyone else can now safely dig in.

Brazil’s Snake Island is exactly what it sounds like, a land mass overflowing with slithering creatures. Seriously overflowing: the government suggests there may be upwards of 4,000 extremely venomous snakes known as Golden Lancehead Vipers that call it home. A couple times each year, scientists are allowed onto the island to study the snakes, but they are the only ones permitted.

12 Italians Want You To Keep Cruising Past: Cruise Ships Are Threatening The City Infrastructure In Venice

The canals of Venice may soon be the lake of Venice as the city is quite literally sinking before our eyes. The proliferation of cruise ships in the area have caused the tide to rise and the infrastructure to subsequently crack. Local residents have said they can actually feel the ground rumbling and their homes shake when the ships carrying thousands of people make their approach.

The extra water traffic is harming sea life, as well. If you don’t feel empathy for those poor people hanging onto their ceramic dishes as the ships roar past, at least feel something for the seafood that is missing from the pasta.

11 No Outsiders: Refuting The Modern World, Islanders On Sentinel Island Keep To Themselves

In a world in which we have access to literally everything with the click of a button, it is hard to imagine living without technology. However, there are still people across the globe that live a simpler existence. Some even avoid outside contact.

The Sentinelese on the Bay of Bengal’s North Sentinel Island is one such group that is completely isolated. This indigenous group steers clear of modern comforts and only interacts with each other. The island is difficult to reach, but there is a report of a fisherman having gone missing when his boat veered too close to the area. So, keep that in mind if you fancy yourself an adventure to the bay.

10 A Numbers Game: Greece Has Cracked Down On Tourism In Santorini

With a population of just over 15,000 people, Santorini is a rather interconnected city where neighbors attend dinner at each other’s houses and the bartenders at the local pub have a consistent following. This Greek gem has been under siege from debt and is now facing another crisis in the form of tourism.

Before the government instituted a cap on tourists allowed to arrive via cruise ship, the city was doubling in population every day of the year. The constant influx was just too overwhelming and the city is still feeling the negative impacts.

9 That's Just Bananas: To Protect The Gorillas, Not Just Anybody Can Go To The Bwindi Impenetrable Forest

If watching endangered gorillas pick mites off each other (at an alarmingly close distance considering the size of the animals) sounds like the perfect vacation, you will be on cloud nine at the Bwindi Impenetrable Forest.

The only catch is that to access the forest through any of the countries it touches (Uganda, Rwanda, the Democratic Republic of the Congo) you have to go with an official tour company. The guides are all trained in gorilla calming techniques and will make sure you don’t get lost, so it’s probably a good idea to heed this requirement.

8 Just Stop: The Colosseum Is Not A Souvenir

The Colosseum is arguably one of the most recognizable landmarks in the world. However, if we keep going at the rate we are, there won’t be anything left of it. While there were always occasional incidents of tourists taking a piece of stone from the site as a souvenir, this practice is now at an all-time high.

With tens of thousands of visitors every day, you can imagine the damage if everyone started doing this. It will cost you a few thousand dollars in fines if you choose to commit such an act and are caught, so you’re better off buying an overpriced item from the gift shop.

7 We're Not Wanted: Vandalized And Under Pressure From Foot Traffic, The Great Wall Of China Crumbles

The Great Wall of China is maintained largely by local individuals on a daily basis that know how much work their ancestors put into the construction and want to see it remain standing. They report back to the government when sections start to crumble, carefully moving large pieces to keep the area safe, and scrub off the recurring graffiti on their own. They return home covered in dust to do it all over again the next day.

Despite these efforts, the wall is deteriorating at a rapid pace that is directly tied to the number of visitors it receives.

6 We Will Never Know: The Vatican's Secrets Will Remain Secret

You need more than a secret code to get into the Vatican’s Secret Archives. In fact, you need special permission and a whole lot of patience if you are looking for something in particular. The pages contained in the archives (amounting to over fifty-three miles of work if it was to be spread out) are all handwritten and not currently accessible anywhere electronically.

The calligraphy/cursive mix of script that was used in the early 1200s is definitely challenging to read, but that might be the least of your worries as you first have to understand the historical way of speech.

5 Wonder Of The World No More: Humans Are Causing The Great Pyramids To Erode

Don’t be the guy that travels all the way to Egypt to climb the pyramids. We repeat, don’t do it. While the public was certainly outraged after seeing footage of a man that did just that, they should actually be more concerned with the daily impacts tourists have on the area.

All that foot (and camel hoof?) traffic is causing the ground to shift ever so slightly but enough that wind patterns redirect and hit the pyramids head on. The resulting erosion, coupled with littering, are packing a punch for this wonder.