Rising from the Giza Plateau, Egypt's Sphinx sculpture is one of the world's most jaw-dropping landmarks. It's enormous, at about 240-feet (73m) long and 66-feet (20m) high, and it's thought to have been built under King Khafre, who ruled some 4,500 years ago. The legendary monument was actually buried right up to the shoulders for centuries, and it wasn't entirely excavated until the 1930s. It's still partially entombed in sand in this 1882 photo, which shows British troops swarming the monument after the Battle of Tel-El-Kebir.
This more modern snap shows the great landmark freed from its sandy confines, with the Giza pyramids soaring in the background. In more recent years, archaeologists have continued digging (both literally and figuratively) and have revealed fascinating snippets about the workers who likely built it. The discovery of a huge store of cattle bones, for example, suggests that a thousands-strong work force feasted on high-quality meats as they toiled away.
If this photo wasn't black and white, you'd probably think it was a modern-day shot. That's because the colossal Pyramids of Giza – built around 4,500 years ago – have changed little over the past centuries. They didn't always look like this, though. According to Smithsonian, the limestone was originally worked and smoothed with a sandstone brick, leaving a polished white finish that glinted in the sun. This picture captures the much more familiar, weather-beaten structures sometime in the late 1800s or early 1900s.
Today the pyramids look much the same as they did around a century ago, right down to the folks riding camels in the foreground. But our understanding of these monuments is constantly changing. For example, archaeologists have discovered curious contraptions that go some way to explaining how the giant landmarks were built. More findings also suggest that the pyramids were held together with a concoction of limestone chippings and mortar, much like modern concrete.
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Taken from a slightly closer angle more than 100 years later, this photograph shows that the Parthenon has changed little over the last century. The columns remain, as does the ruined portico, both rising up amid scattered boulders. Now fragments of the ancient Greek temple are housed (sometimes controversially) in museums around the world, from Paris to Vienna. Among the most impressive are the Elgin Marbles, a series of intricate friezes and sculptures at the British Museum.
Hewn from mighty bluffs of red sandstone, the Treasury (or Al-Khazneh) is the greatest wonder left behind in the ancient city of Petra. The city is thought to have thrived from around 400 BC and experts believe that the elaborate Treasury served as a royal mausoleum. Europeans tracked down the incredible ruins in the early 1800s and the site gradually established itself as a tourist destination. This close-up shot taken circa 1900 shows off the Treasury's stunning columns and carvings.
The gorgeous salmon and burnt-orange colours of the Treasury are on full display in this modern-day shot, but apart from that the two snaps differ very little. Nevertheless, the ancient structure, which typically receives around one million visitors per year, has felt the impacts of tourism. According to studies, the precious sandstone here, including that of the Treasury's façade, is wearing away due to tourist activities including walking and sitting. The site has been protected under UNESCO since 1985.
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This mammoth stone circle has been baffling experts for time immemorial. The impossibly perched henge is thought to date back some 4,500 years, yet its exact purpose and usage still remains a mystery. Its stones are carefully arranged to line up with the movements of the sun, so it could have served as some kind of Neolithic calendar or, more likely, a place of worship and/or a burial site. Over the last century, the site has been carefully restored and studied further. This photo from 1901 captures a landmark dig and restoration project overseen by renowned British engineer William Gowland.
This image shows Stonehenge more than 100 years later. Gowland's wooden frames and equipment are long gone, but experts are still trying to understand the fascinating monument. The most recent excavations have turned up relics including deer antlers, pottery and burial sites. New evidence has also linked Stonehenge to a site called Waun Mawn in Pembrokeshire and archaeologists now believe that the monument was erected in Wales, before being transported to its current site on the Salisbury Plain.
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The carved human figures, or moai, scattered across Chile's Easter Island really have to be seen to be believed. The tallest among them soars to well over 30 feet (9m) and although it's not known exactly when these colossal busts were built, there's no doubt they've watched over the island for centuries. Extensive restoration projects were carried out in the mid-20th century – here archaeologists work on a towering moai circa 1969.
Pictured here about half a century later is Ahu Ko Te Riku, a moai in the Tahai complex, looking over the South Pacific Ocean with its striking restored coral eyes. Modern-day archaeologists are still trying to work out the reason why these brooding statues were erected. The most recent studies have linked their locations to the presence of fresh water sources.
You can barely turn a corner in Rome without coming face to face with some glorious ancient wonder. Among them is the Arch of Constantine, which enjoys pride of place right next to the fabled Colosseum. The triumphal arch is decorated with elaborate reliefs and friezes, and was built in AD 315 to celebrate Constantine's victory over Maxentius at the Battle of Milvian Bridge. It's long been earmarked by tourists as a photo spot: this shot shows a trio of smiling visitors posing before the monument circa 1930.
The Romans revered the hot springs that bubble in the ancient city of Bath. Convinced of the water's healing properties, they built an extravagant bathhouse and a temple devoted to goddess Sulis Minerva. But after Roman rule ended in Britain, the baths fell into disuse and disrepair. The site was rediscovered in the 1880s and large parts of the Great Bath were uncovered and eventually opened to the public in 1897. Tourists look across the ruins of the Great Bath in this photo taken in the late 19th century.
Pictured here more than a century later, the Great Bath is glittering once again. It's no longer possible to bathe in the waters, but modern visitors to the site can still immerse themselves in ancient Roman history. Typically tourists wander around the Great Bath and drink in the Temple Courtyard, where the Romans would have worshiped goddess Sulis Minerva. The Thermae Bath Spa, which is fed by those famous hot springs, is right on the doorstep too.
In this present-day night shot, Pula Arena is juxtaposed with its more modern surroundings. The harbour is crammed with sleek sail boats and lights glitter on the water at dusk. Today history buffs can explore the amphitheatre and it also typically hosts concerts, dance shows and festivals in place of bloody gladiatorial battles.
Excavations and restoration projects began at the site in the late 19th century and into the 20th century, and Baalbek's ancient structures underwent repairs over time. This recent shot shows the Temple of Bacchus looking remarkably more pristine than it did in the 1880s. It also came under UNESCO's protection in 1984.
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Just under a century later, travellers are still flocking to this fascinating Mexican site. This modern photo shows tourists gathering at the foot of the towering structure and also climbing the steps that lead up to its summit. The entire site is ripe for archaeological discoveries too. Secret tunnels and a chamber were found under its sister landmark, the Pyramid of the Moon, in the last decade.
You might be familiar with images of Chichén Itzá – an ancient Maya city known for landmarks like the grand, stepped pyramid of El Castillo. But this photograph, taken circa 1859–1860, shows the famous archaeological site in a rather different state. The city was once home to tens of thousands of people, flourishing around AD 600, when it was a political and commercial heartland of Maya civilisation. Yet it began to decline before the Spanish conquest. It's pictured here ruined and covered with vegetation in the mid-19th century.
Through the early 20th century, extensive work was carried out at the site: vegetation was cleared, ancient relics were excavated and striking monuments were restored. This photo shows a section of the site in the modern day, no longer swallowed by trees and shrubs. Exciting new developments are occurring here too. Come 2022, Chichén Viejo, a new jungle-clad fragment of the site, will open to the public. Unlike in the past, though, the vegetation won't be cleared. Modern archaeologists have realised that the overgrowth acts like a protective "skin" for the ruins and should be left as is.
The temple's sleek platforms and pillars look markedly more intact and pristine in this modern shot than they did in the early 20th century. The site underwent major excavations and reconstruction work from the 1960s onwards and the results were magnificent. Statues have also been excavated, and modern-day tourists can explore the complex and learn about the fascinating life of this female pharaoh.
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The figures, buried close to the mausoleum of Qin Shi Huang (founder of the Qin dynasty), are thought to date to the 3rd century BC and were likely created to protect the late emperor in the afterlife. This current-day photograph shows the site after further excavations, which revealed even more terracotta effigies. Work at the site is ongoing with archaeologists suspecting that yet more soldier-filled pits will be uncovered.
A similar view of Pompeii's Forum is captured here in the present day. Still the ruins are painstakingly preserved and you can spot tourists milling about the ancient remnants. Archaeological work continues to uncover more about Pompeii's residents too. From ongoing excavations, experts have been able to reveal everything from their political ideals to their lunch choices...
Another ancient site once veiled by greenery, Tikal, in northern Guatemala, was an ancient Maya city and a ceremonial hub. It bloomed from about 300 BC and was eventually populated with great plazas and pyramids, many of which have been preserved for posterity. This is an early photograph of the site, snapped around 1882. The breathtaking ruins are choked by vegetation and the floor is littered with trees. The photo was taken by British explorer Alfred Maudslay, who was involved in mapping and excavating the site during the 1880s.
Now the ruins, part of Tikal National Park, usually draw tourists from all over the globe and a museum, opened in the 1960s, sheds further light on the ancient settlement. Best of all, it seems that there's much more of this fascinating site to discover. In fact, studies using LiDAR technology have suggested that Tikal is four times larger than experts originally thought.
America's ancient landmarks are often forgotten, but sites across the States offer intriguing insights into the country's earliest settlers. Among them is Mesa Verde National Park and its Cliff Palace, an incredible 150-room dwelling built up by Ancestral Pueblo people from around AD 1190 to 1260. It's pictured here in the 1930s, and you can see tourists wandering about the walls and kivas.
Little has changed over the past decades and this could be the same image, just in vibrant colour. It's typically possible to explore the Cliff Palace on a ranger-led tour, peeking into ancient rooms and climbing steep ladders. In 2021, the park was also certified as an International Dark Sky Park – the 100th such site in the world.
Fast-forward to the modern day and the ancient wonder is a bustling tourist hub: once-quiet roads hum with traffic and tourists can be seen peering out from its bold archways. Despite the landmark's age, we're still discovering its secrets. Tiny details like little red numbers painted above those archways offer hints about its history: in this instance, the numbers suggest that Roman spectators followed an ordered seating plan. A new, retractable floor is also set to be installed at the Colosseum, allowing tourists to stand right where gladiators once clashed.
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The scale of China's Great Wall is immense: it wriggles out for around 13,171 miles (21,197km) according to the most recent estimates and is punctured by hulking watch towers. While the wall's roots go as far back as the 7th century BC, the best-preserved sections (one of which is pictured here) date to the Ming Dynasty (from the 14th to the 17th centuries). The most touristed segment, at Badaling, was also restored in the 1950s, the same decade that this photo was captured.
Fast-forward almost three quarters of a century and the wall typically attracts millions of visitors each year. In recent years, the wall's 'wildest' parts have been given some attention too. The Jiankou section is one of the structure's most famously remote and perilous fragments, spilling over soaring mountains in a spool of rubble and ruin. However, high-tech renovation efforts occurred in 2019 and beyond, in an effort to make the area safer for visitors and to preserve it for posterity.
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