Cruise the canals of Venice on a Gondola. Swim beside the Great Barrier Reef. Stand beneath the shadow of the Taj Mahal. Spot alligators in the Everglades. Take in the vistas of Rocky Mountain National Park.

If any of these are items on your travel bucket list, you might want to cross them off sooner rather than later. All of these famous destinations are under threat of deterioration and destruction within our lifetime.

While global warming and sprawling development have put many legendary places in at least eventual danger, these five are predicted to change drastically as soon as the next few years.

Venice

The same canals that made Venice famous are now threatening the city’s future. The historic city made up of 118 separate islands sinks 2 ½ inches deeper into the surrounding water each decade. Combine that with rising water levels in the Adriatic Sea and you have a recipe for an underwater city in the not-so-distant future.

According to Frommer’s 500 Places to See Before They Disappear, St. Mark’s Square, the city’s center, flooded 10 times a year in the early 1900s, but by the 1980s it was submerged on average over 40 times annually. Recently, it is not uncommon for the square to flood that many times in between September and March alone.

Problems may continue to mount as Venice hosts an average of 60,000 tourists a day, twice what its infrastructure can handle. Over 1,000 mega-sized cruise ships squeeze into the cities port each year and boats navigating the canals erode mud banks and pylons necessary for the buildings’ stability.

The Italian government has promised UNESCO they will work to save Venice, but its problems have not been solved yet. Although a project with an expansive system of underwater flood-control barriers is supposed to be completed this year, critics are skeptical about its ability to combat rising sea levels. If not, another plan must be made to preserve such a unique city.

The Everglades

There is no place on earth like the Florida Everglades. These subtropical wetlands are the only place in the world where crocodiles and alligators share the same swamps and the only place where a Florida panther can still be found. Over 20 other endangered species also reside within the wetlands.

Unfortunately, these rare animals are only more endangered now since the Everglades have been reduced to half of the area it once covered. Irrigation for suburban development and farming has diverted 60 percent of the Everglade’s water. The US. Army Corps of Engineers set aside 1.2 million acres of land for sugar farming, which is especially harmful and blocks the flow of water from Lake Okeechobee to the Everglades. Also, invasive species, such as the recently destructive Burmese Python, reduce native animal populations in the areas that remain.

Activists and the government agencies are working on the preservation and restoration of the wetlands. Congress passed the Comprehensive Everglades Restoration Act in 2000, but funds and methods still need to be worked out. Unfortunately, species like the Florida panther don’t have time for that, as they may be gone within 40 years if their habitat continues to shrink.

Fortunately what is left of the Everglades is still very much alive. The 1.5 million acre Everglades National Park combined with Biscayne National Park, Big Cypress National Wildlife Refuge and the Florida Keys National Marine Sanctuary all work together to protect the area and are great places for visitors to experience the unique ecosystem.

Rocky Mountain National Park

Rocky Mountain National Park is the essence of Colorado with high elevations and rugged mountains with rocky tops and pine-covered sides. However, these once lush green conifers may not keep their color for long. Pine beetles are already taking over the hillsides of Colorado, reducing full pines to sickly burnt orange skeletons.

The offending beetle is surprisingly not an invasive species, but has become a destructive epidemic nonetheless. Once a pine beetle infests a tree, nothing can be done to save it and a tree killed by beetles one year will produce enough beetles to kill two trees the following year, making isolation of the beetle epidemic nearly impossible. While birds such as woodpeckers and other insects feed on the beetles and their larvae, natural controls are not enough to subdue an epidemic of these beetles. While other prevention methods are available, they are time-consuming and expensive and require identification of which trees haven’t already been infected, which is a difficult task.

Luckily for Rocky Mountain National Park, not all of its pines are susceptible to the beetle. According to Leah Etling, a Santa Ynez Valley Journal writer, firs and spruces are safe from the current beetle epidemic, leaving the southeast corner of the park preserved. As for those areas already affected, in five to seven years the trees will begin to grow back, but it will take decades for the mountains to be covered as they once were.

Taj Mahal

While the Taj Mahal is still magnificent to behold, it is facing deterioration Mugal Emporer Shah Jahan could not

foresee when he ordered it to be built in memory of his wife. Although the 17th century mausoleum still retains its grandeur from afar, a closer look shows yellowed marble corroded by air pollution and the nearby Yumana River is drying and polluted.

The Indian government has taken steps to prevent further deterioration to the exterior of the Taj, but much of the restoration has been sloppy. New industry has been banned from Agra and only non-polluting vehicles are allowed in the vicinity of the great monument, but the exterior continues to deteriorate from existing pollution and gasses emitted from the contaminated river.

Unfortunately, an even more pressing, lesser-known matter plagues the Taj Mahal. The foundation of the mausoleum, is built atop an intricate system of wells with wooden structures, that remains stable only with moisture. Because the Yumana River now runs dry from overuse, sometimes for months at a time, experts fear the wood may crack and disintegrate, causing the collapse of India’s greatest attraction within two to five years.

The doomed fate of the Taj Mahal is speculative, but the World Monuments Fund considers it at risk. While the preservation of this renowned monument is most important, one would hope its deterioration will highly importantly cause improved standards of living with a cleaner river and air for the people of Agra.

Great Barrier Reef

It’s hard to believe that a reef so large it can be seen from the moon could be in danger of disappearing, but Australia’s Great Barrier Reef is facing some serious problems.

According to research by the University of Queensland, if temperatures continue to change as climate experts expect, the reef-building corals that make the Great Barrier Reef possible will no longer exist within the next few decades. Increasing temperatures that inhibit the reef’s calcification process and ability to create new coral may push it to extinction within 50 to 100 years.

Reefs are a balance between calcification and erosion and when the temperatures become too warm for the calcification, erosion takes over. A one-degree temperature change accounted for deterioration of the reef in the last decade, and it is expected to increase between 2 and 6 degrees over the upcoming 10 years.

The Australian government is very concerned about the reef’s future, both from an environmental and tourism drawing perspective. However, temperature changes and water level fluctuations facing the reef are widespread and difficult to fix. Many fear, before long, the reef will be reduced to a theme park reproduction.

We all hope that the Taj Mahal will be more than a pile of rubble five years from now and that the next generation won’t have to go to a museum to see the Great Barrier Reef or the Everglades. If these places are preserved and respected, as they deserve, that may not be the case. However, if you’re dying to be serenaded by a gondolier on the canals of Venice or to snorkel at Australia’s famous reef, then go while you are able, because their futures are still uncertain.