The 21st century has brought its fair share of challenges, from political tensions and civil wars to rising crime and natural disasters. That means some of the 20th century’s most popular holiday destinations are now off-limits to tourists. We’ve taken a look at the once-loved travel hotspots that are now deemed too dangerous to visit.

Once a popular tourist hotspot in the 1970s, Iraq is a fascinating country full of ancient archaeological sites. Decades ago, tourists could take in historic sites such as the ancient cities of Ur, Uruk and Babylon, the 10th-century al-Askari shrine and the archaeological digs in the city of Nineveh.

But the warn-torn country has long been off-limits to tourists, with a high risk of terrorism, violence and kidnapping. Many of the priceless historic sites tourists have been attacked, looted and rampaged, such as the Mosul Museum and Libraries, the city of Nineveh and the tomb of the Prophet Jonah (pictured).

Before Yemen’s devastating civil war made visiting the country impossible, tourists were fascinated by its capital, Sana’a. With its distinctive, multi-storey buildings decorated with geometric patterns, a history dating back thousands of years and its significance in Islam, it was one of Yemen’s prime attractions.

However, to see this old city now would be to put your life in danger: governments from all over the world advise their citizens to stay away from Yemen, and if they're there already, advise them to leave immediately. The fascinating site has been damaged due to armed conflict in the country, with many of its buildings left in a devastating state of disrepair.

Anyone with even a passing interest in nature would be fascinated by Yemen’s fairy-tale, UNESCO-protected Socotra archipelago. It's famous for the distinctive dragon blood trees and rich biodiversity: one third of its plant life can’t be found anywhere else on our planet. Adventurous travellers who made the journey to Socotra were rewarded by a fascinating array of plant and animal life, not to mention unspoiled beaches and coral reefs.

All over Yemen, the ongoing civil war and risk of terrorism makes the country an extremely unsafe place to be. This sadly does not exclude the Socotra Archipelago, meaning it’s off limits to tourists for the foreseeable future.

At the end of the 20th century, tourism to Mali was booming, and by the beginning of the 21st century, visitors were coming to the country in their hundreds of thousands. A primary reason for visiting the country was to see the ancient city of Timbuktu (pictured), a place UNESCO calls “an intellectual and spiritual capital”, home to three great mosques and one of the world’s earliest universities.

The country’s tourism boom was short-lived, however: conflict ensued after a military coup in 2012 and now it's a seriously dangerous place to be. Terrorism and kidnapping is a very real threat, and there is a state of emergency in place. Timbuktu was sadly put on UNESCO’s list of sites in danger in 2012 after the violence in the country escalated.

Decades ago, Pakistan was a prime tourist destination: in the 1960s and 70s, tourists would visit the country as part of the “hippie trail”, which also passed through now-dangerous countries like Afghanistan. In Pakistan, backpackers would cross the Khyber Pass (pictured) and make their way to destinations like Peshawar, Lahore and Karachi as cheaply as possible, seeking spiritual enlightenment along the way.

However, in the 21st century, tourists would have a very different experience travelling through Pakistan. There’s a high risk of terrorism, kidnap and sectarian violence throughout the country, with foreigners at a high risk of being targeted.

In the 20th century, Somalia was on many travellers’ bucket lists and was seen as an aspirational and safe place to visit: it was known as the "Pearl of the Indian Ocean". Tourists enjoyed lolling on unspoiled beaches, coming face-to-face with a fantastic array of wildlife and seeing dramatic mountain landscapes.

However, once the civil war began in 1991, the country’s tourism industry collapsed. It’s now unsafe to visit: there is a high risk of terrorism and kidnapping, especially in tourist areas including hotels and restaurants.

Before the current upheaval in the country, hundreds of thousands of tourists came to visit Libya’s capital city of Tripoli. They enjoyed shopping in bustling souks, taking in the architecture at a variety of spectacular mosques and visiting historic sites such as the Citadel of Raymond de Saint-Gilles (pictured).

The country was hit hard by civil war in 2011, and as such, tourists are unable to visit Libya, including its capital, in 2018: the country is not issuing tourist visas and those in the country are at a high risk of terrorist attacks, kidnappings and being caught in violent clashes.

It’s no surprise that tourists were curious to see the Old Town of Ghadames, a UNESCO World Heritage Site. The Berber town, which stands in an oasis, is one of the world’s oldest pre-Saharan cities.

However, tourists hoping to see the fascinating town today will have to put those dreams on hold. As well as the total ban on visiting Libya, the future of the Old Town of Ghadames is uncertain: along with the other World Heritage Sites in Libya, the town has been placed on the UNESCO danger list because of the damage inflicted by the country’s current conflict.

A popular destination for several decades, tourists have long flocked to the beautiful islands of the Philippines, returning time after time to enjoy their unspoiled white-sand beaches, glittering waters and magical underwater life.

However, despite its brochure-worthy appearance, not all the Philippines’ islands are safe to visit in the 21st century: tourists should steer clear of western and central Mindanao and the Sulu archipelago due to crime, terrorism and civil unrest.

Antakya, also known as Antioch, was once a popular Turkey holiday spot for those with a fascination for all things archaeological. History buffs would take in the Hatay Archaeology Museum, full of priceless Roman and Byzantine mosaics, and the UNESCO-protected St Pierre Church (pictured).

But Antakya’s close proximity with the Syrian border makes it unsafe to visit at this time. There’s a risk of terrorism throughout the country, but travel near the Syrian border is particularly advised against.

In the 1950s and 60s, Lebanon was a favourite destination of wealthy jet-setters. They holidayed regularly in Beirut, choosing the city for its 5-star hotels, luxurious restaurants and beach clubs, Paris-style cafés and buzzing nightclubs. Some famous fans of Beirut included Brigitte Bardot and Peter O’Toole, who enjoyed the city’s “Paris of the Middle East” vibes.

However, once civil war broke out in 1975, the country’s touristic fortunes were devastatingly reversed and have been unstable ever since. In Beirut, as in the rest of the country, the security situation can deteriorate quickly and Britain's Foreign & Commonwealth Office advise against travel to certain areas of the city, particularly around the airport. Terrorism is also an issue, with attacks likely throughout the country, especially in tourist spots like markets or shopping malls.

The Phoenician city of Baalbek, a UNESCO World Heritage Site, was once one of Lebanon’s prime tourist attractions. The sprawling Roman ruins, with its impressive complex of temples and well-preserved architecture, was called “one of the most impressive testimonies of the Roman architecture of the imperial period” by UNESCO.

But the fact Baalbek is so close to the Syrian border is a big red flag for governments, many of which advise their citizens against travelling to the impressive Roman ruins. This has resulted in a dramatic fall in visitors and has deeply impacted the local economy, which once thrived on regular tourist visits.

As Sinai’s most important religious site, St Catherine’s Monastery (pictured) is a significant location for followers of Christianity, Islam and Judaism, and was regularly visited by intrigued tourists on day trips from Sharm El Sheikh. Founded in the 6th century, the monastery is located at the foot of Mount Horeb, where, according to the Old Testament, Moses received the ten commandments.

But the monastery’s location on the Sinai Peninsula makes it an unsafe spot for tourists at this time. Many governments have warned their citizens not to visit the Sinai Peninsula due to threats of terrorism and frequent attacks both on security forces and civilians.

Thinking of Syria in 2018 will no doubt conjure up distressing images of the current civil war, which has killed hundreds of thousands of people. But before the conflict began, the tourist industry made up 14% of Syria’s economy, with visitors journeying from far and wide to take in fascinating historic sites, such as the ancient ruins of Palmyra (pictured). The UNESCO World Heritage Site is one of the ancient world’s most valuable cultural centres and was a major tourist draw.

In addition to the devastating human losses caused by the war, many of the priceless archaeological sites once popular with tourists have been utterly destroyed. Palmyra has faced repeated attacks, with UNESCO calling the destruction of the ruins a “war crime and an immense loss for the Syrian people and for humanity”.

Syria’s capital, Damascus, was another of the country’s tourist hotspots. One of the oldest cities in the Middle East, and one of the oldest continually-inhabited cities in the world, Damascus has 125 monuments from different historical periods. When the city was safe to visit, the 8th-century Great Mosque of the Umayyads (pictured) and the Citadel of Damascus were huge tourist draws.

All of Syria, including its capital, is now one of the most dangerous places to visit in the world. Damascus has been deeply affected by the war, with many of its most important monuments damaged: it has been placed on UNESCO’s List of World Heritage Sites in danger.

Afghanistan has endured such turmoil and instability over the past few decades that it’s hard to imagine a more peaceful time. Yet in the 1960s and 70s, the country’s capital city Kabul welcomed in tens of thousands of tourists. Visitors flocked to the city to enjoy impressive architecture, such as the Darul Aman Palace, educational exhibitions at the Kabul Museum and the magnificent, UNESCO-protected Gardens of Babur.

But the city is far less likely to welcome visitors today. There’s a high risk of terrorism and kidnapping throughout not just the capital but the entire country, and Afghanistan is also in a major earthquake zone. Many of the city’s most important historic sites and priceless artefacts, such as the Darul Aman Palace (pictured), have been left in tatters, resembling nothing of their former glory, after the devastation of the war.

One of the prime reasons for tourists to visit Afghanistan when it was safe was to take in the majestic Buddhas of Bamiyan. The world-famous landmarks were constructed in the 6th century, and were once the tallest standing statues of Buddha ever made.

The Buddhas were blown up by the Taliban in 2001, leaving cavernous holes in the cliff face as the only evidence of their previous existence. UNESCO described it “a significant loss to the country and to humankind”.