Welcome to the era of bucket list travel where record-breaking numbers of tourists set out to conquer the world’s most beautiful destinations. But what happens when a handful of the same destinations top everyone’s must-see list? Overcrowding, and often, damage to the sites.

From Peru to China, Italy to Antarctica, an over-abundance of tourism is causing havoc on resources. The swell of travelers has created the need for greater infrastructure: more flights, lodging, roads, and trash disposal. That means a growing number of destinations have been forced to make difficult yet strategically important decisions to balance present demand and economic gain with future sustainability.

Caught in a balancing act, governments and tourist boards around the world are implementing programs to protect vulnerable environments while welcoming present-day travelers in a manageable flow. What does this mean for travelers? If you dream of seeing a hot-list destination, expect higher costs and more regulation.

Supporting local tour operators and vendors committed to sustainable practices could mean experiencing one of the world’s wonders with less impact, people, and pollution, while helping to ensure a special spot exists for future generations. Now, that’s something for the bucket list. Here are 10 destinations in search of a more sustainable path.

1. MACHU PICCHU // PERU

Protected by dense jungle, the Incan city lay in secret for 400 years until its scientific discovery in 1911. As if to make up for lost time, travelers since have rushed the citadel in ever-increasing numbers. In 2012, when annual visits surpassed a million for the first time, the need for regulation became evident.

With nudging from UNESCO, Peru’s government announced upcoming changes. Today, the daily number of visitors is capped at 2500 and multi-day treks are restricted to small groups that follow three specified routes. All trekkers must also purchase a permit and use an official guide.

Implementation of time limits for areas prone to bottle-necking—along with unpopular “Keep Moving” signs—have caused grumbling from visitors, but they’ve also had positive effects. While tourists sacrifice the ability to roam freely, they are rewarded with reduced trash on trails, less overloaded porters, and access to a professional guide for insight into Peru’s culture, past and present.

2. MOUNT EVEREST // NEPAL & CHINA

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No destination exemplifies the struggle over overcrowding and regulation more dramatically than the world’s highest peak. Over the last decade, as demand to summit climbed, the range of trekking operators and issued permits expanded. The atmosphere at base camp was often described as circus-like, with climbers of all skill levels making the push. It even became possible to bypass the multi-day trek and arrive at base by helicopter (along with previously unthinkable supplies like sushi for dinner).

Demand to climb Mount Everest has declined since 2013, due to seasons marred by natural disaster, climber versus Sherpa altercations, mountain closings, and massive loss of life. Still, no one doubts that the desire to summit will eventually kick in again.

Environmental activists and climbing enthusiasts hope the lower number of visitors will offer the opportunity for recalibration. While climbing revenue is essential to the local economy still recovering from a devastating earthquake, fostering a healthy infrastructure is key to future sustainability. Future restrictions include higher permit fees and proposals to ban novice climbers.

3. SANTORINI // GREECE

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From the outer deck of a massive cruiser, tourists can take in the dramatic cliffs of Santorini, which shoot nearly 1000 feet above the Aegean Sea. Concerns that the number of visitors arriving—about 800,000 visitors per year—will soon overwhelm the island’s infrastructure prompted local officials to consider some adjustments.

The government announced limits on the number of visitors arriving by cruise ship during high season, May to October. Starting in 2017, a maximum of 8000 tourists will be permitted to embark daily, a reduction of approximately 20 percent of current totals. While this change will make a dent in the island’s people crush, similar limitations have yet to be placed on flight arrivals.

4. KOH TACHAI, KOH KHAI NOK, KOH KHAI NUI, AND KOH KHAI NAI // THAILAND

Some of Thailand’s most beautiful islands have announced major changes and prohibitions for tour and boat operators. Citing damage caused by an increasing amount of speed boats shuttling ever-increasing numbers of tourists to the area’s pristine beaches and reefs, Thai authorities made travel industry headlines by unveiling plans to close off the island of Koh Tachai, part of Similan National Park. The area is currently closed for monsoon season, but come October 15 it will not reopen.

Weeks later, officials revealed plans to close three additional islands, Koh Khai Nok, Koh Khai Nui, and Koh Khai Nai. This chain of islands, popular with day-trippers from Phuket, routinely saw 60 speedboats a day and has become perilously close to losing its famed coral reefs. Surveys are underway now on approximately 40 of Thailand’s other natural assets with more changes in tourism management expected.

5. CINQUE TERRE, ITALY

When park officials recently announced plans to reduce the number of annual visitors to this chain of five centuries-old, cliffside villages to 1.5 million—down from a high of 2.5 million visitors in 2015—the news wasn’t well received.

Still, the plan’s rollout may have slowed, but officials hope to unveil a new ticketing system, requiring advance purchase to visit the villages by 2017. Other changes in the works include development of a “people counting” app to track crowd flow within each town and along trails connecting one to another.

6. GALAPAGOS ISLANDS // ECUADOR

UK-based Galapagos Conservation Trust estimates that the islands saw a mere 200 tourists back in 1934. Fast forward just over eight decades to 2015, and visitor numbers jumped to a record 224,755, according to the Galapagos Conservancy.

With the increasing amount of tourists have come more job-seeking residents, more infrastructure, and more pressure on the fragile environment. In 2007, the islands were placed on UNESCO’s endangered list, prompting changes including limiting tourists to specific land and scuba areas.

Although the islands exited the endangered list in 2010, the problem is far from resolved. In an effort to limit the number of ships arriving as well as direct tourism revenue to more locals, officials have encouraged land-based visits. Boat-based tourism is now tightly regulated by the number of nights in the archipelago as well as size and duration of excursions.

7. ANTARCTICA

A record 46,265 visitors boarded massive cruise ships bound for the icy waters during the 2007 to 2008 season. Fears of irreversible damage prompted the 48 member nations of the governing Antarctica Treaty to announce a new rule book in 2009. The agreement limits the size of cruise ships to 500 passengers as well as requires operators to coordinate landings, reducing the number of boats per site. Shore-going passengers were capped to 100 at a time, with one guide per 20 people required. And in 2011, additional regulation went into effect banning the use and carriage of heavy fuel which officials say has reduced the size of “cruise-only” ships.

8. SEYCHELLES // AFRICA

With its blue skies, white sand, and turquoise waters, Seychelles—a collection of 115 island off of East Africa—is known for its serene palette. The area has attracted high-profile visitors including the Duke and Duchess of Cambridge as well as actor George Clooney and wife Amal, in turn spurring more visitors.

In April 2015, the minister of tourism and culture said plans were underway to limit the amount of visitors, stating the islands were attracting over 250,000 people a year, three times the number of residents. The proposed changes will be put into effect by regulating the number of hotel rooms allowed on each island.

9. MOGAO GROTTOES // NORTHERN CHINA

The 1600-year-old cave complex in Northwest China along the famed Silk Road route features elaborate Buddhist frescoes and sculptures, attracting over a million visitors a year. To prevent damage to the cave’s unique paintings and features, one of China’s first UNESCO World Heritage Sites established a new policy in 2014.

Tickets must be purchased in advance and are limited to 6000 visitors per day. (although oddly there are also 12,000 “emergency tickets” for peak season). To keep visitors moving and prevent bottlenecking, officials got creative. A film, developed to give visitors an overview of the site’s history and significance, is shown before entering the caves in hopes of cutting down explanation time inside. In an effort to keep humidity and air quality surrounding the precious frescos in check, visitors are now limited to approximately five minutes per cave.

10. POMPEII // ITALY

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The Roman city, frozen in time by an epic eruption from nearby Mount Vesuvius, was said to have a population of 11,000. In comparison, a recent one-day count of visitors through the gates clocked in at triple that number. So Italy’s Ministry of Culture announced plans to cap the daily number (about 35,000) at 15,000.

The site’s massive popularity had begun resulting in not only damage to Roman roadways and steps, but also the site’s priceless frescos, which are vulnerable to changes in humidity. Officials hope the new caps encourage visitors to explore less well-known sites including the more compact Herculaneum.