Researchers continue to learn new things about ancient civilizations, which can be better understood by studying architectural structures that have stood the test of time. Dedications to gods and other religious figures can be found at many old historical locations.

A lost city is an intriguing idea. It sounds more like science fiction than reality, but there is an ancient civilisation lost to time and space that contains knowledge of how early people lived in an era before modern technology. Yet ancient civilizations' remains have frequently been discovered.

It's not always the case that these cities are lost or that they are "discovered." It might be disrespectful to Indigenous populations' local knowledge and traditions to refer to European explorers as "discoverers".

However, excavations and restorations of historical sites are frequently directed by explorers, archaeologists, and diplomats from Europe. These historical landmarks shed light on earlier cultures, climatic conditions, conflicts, and educational systems.

Ten archaeological sites are shown here, along with photos of them before and after restoration.

Chichén Itzá, Yucatan, Mexico

The ruins of an ancient city called Chichén Itzá are located in Yucatán, Mexico. The city's founding took place between AD 415 and 435. Chichén Itzá entered a new period in AD 957 when the Toltec King Kukulkan and his followers moved from central Mexico to take control of the city.

Chichén Itzá mixes the Toltec and Mayan cultural and architectural influences. The Mayans created one of the greatest ball courts in all of Mesoamerica by leveling the ground where they erected their city and paving the streets that connect all of their structures.

When the indigenous Yucatec Maya rose out in revolt against the Itzá emperors in 1440, the city was abandoned. Following the uprising, the Itzá split up and abandoned Chichén Itzá.

On one of his journeys to Central America, the American explorer John Lloyd Stephens rediscovered Chichén Itzá in 1841.

Sylvanus Morley, an archaeologist, began his dig only in 1924. When Morley and his group finally arrived to Chichén Itzá, the city had been completely destroyed by native vegetation and overgrown.

As of 2007, the city was chosen as one of the new Seven Wonders of the World and is now a UNESCO World Heritage Site.

Tikal, Guatemala

Although archaeologists disagree on the exact period of Tikal's settlement and growth, many think it was established about 600 BC. Many of the city's structures are thought to have been constructed between AD 250 and 900.

The Mayan civilization's economic center and home to more than 60,000 people before it fell, Tikal. Archaeologists dispute on the causes of Tikal's abandonment, however others put it down to cultural and economic problems. According to a recent study, during a severe drought, drinking water may have been contaminated by mercury and harmful algae, which may have caused everyone to flee the city.

It took until 1848 for the first authorized excursion to the remains. Although it is thought that humans were residing there in the 18th century, according to various Guatemalan archives.

During the ten-year period from 1956 to 1966, Tikal was excavated and restored, in large part because to archeologists from the University of Pennsylvania.

In the 1970s, the park was designated a UNESCO World Heritage Site, and research continues to this day. In the midst of Tikal's ruins, a new structure was just uncovered in 2021 that may provide information about the city's long-lost past.

Mayan Temple of the Inscriptions, Chiapas, Mexico

The Mayan metropolis of Palenque was situated in what is now southern Mexico. The city of Palenque and its temples were founded in AD 432 and subsequently developed between AD 615 and 683. The Temple of Inscriptions, which is thought to be the largest Mayan funeral pyramid, is located at Palenque.

Father Pedro Lorenzo de la Nada, a Spaniard passing through Mexico in 1567, made a new discovery of Palenque. When Lorenzo came across Palenque, it had been abandoned.

The city was considerably smaller than other nearby Mayan cities, with an estimated peak population of just over 6,000.

In 1987, Palenque was designated a UNESCO World Heritage Site, and since then, it has been crucial for academics studying the Mayans. Despite not being the largest Mayan city, Palenque's temples and tombs have taught scholars a lot about Mayan sculpture, architecture, and language.

Terracotta Army, Shaanxi Province, China

A terracotta man's skull was struck by a farmer in 1974 as he was digging a well on his property. The farmer, Yang Zhifa, informed the authorities of his find. Soon after, a group of archaeologists found thousands of terracotta figurines beneath Zhifa's farm, not just one.

There are thought to be 8,000 terracotta soldiers of varying ranks and roles among the four trenches that were found. According to National Geographic, the soldiers, who are now gray and brown, were thought to have been painted with vibrant hues when they were first made 2,200 years ago.

The greatest funerary complex in the world, the one for Qin Shi Huang, the "first Qin Emperor," is thought to include the Terracotta Army.

For the time being, it is a UNESCO World Heritage Site.

Cliff Palace, Mesa Verde, Colorado

Cliff Palace was unintentionally discovered in 1889 by ranchers seeking for stray cattle, just like the Terracotta Army. Cliff Palace, which had 150 apartments, 23 kivas (subterranean chambers), and could accommodate 100 people, is thought to have been constructed between 1260 and 1280.

The ranchers, who were all brothers, removed various artefacts from the site and made an effort to sell them to local museums. They met the Swedish explorer and researcher Gustaf Nordenskiöld during their trip, who was intrigued by their discoveries.

Ashes from previous fires, rubbish collected from building levels, and a mummified corpse were among the relics that Nordenskiöld brought back to Sweden. Due to Nordenskiöld's efforts, Cliff Palace received widespread media attention.

Virginia McClurg fought for the preservation of Cliff Palace in response to the attention that Nordenskiöld's deeds attracted. Cliff Palace gained widespread support and was essential to its designation as a national park thanks to McClurg.

The Great Ziggurat of Ur, modern-day Iraq

Around 2100 BC, the Great Ziggurat of Ur was created in Mesopotamia, which is present-day Iraq. In Mesopotamia, ziggurats were built with temples on top to commemorate a city's patron deity.

The temple at the top of the Great Ziggurat of Ur, which is composed of 720,000 33-pound baked bricks, has been lost to the passage of time, but the base is still intact. The Euphrates River, upon which Mesopotamia developed its civilization, shifted its course by the sixth century BC. The city became uninhabitable without the river's water, and both the Ziggurat and the city that encircled it were abandoned.

An excavation of the Ziggurat of Ur was started in the 1920s by British archaeologist Dr. Leonard Wooley in collaboration with the University of Pennsylvania and the British Museum.

In its lifetime, the Ziggurat has undergone two restorations. The upper terraces were rebuilt for the first time by the Babylonian King Nabonidus in the sixth century BC. Saddam Hussein carried out the subsequent reconstruction 2,400 years later. Hussein rebuilt the Ziggurat's lower base and the wide staircases that reach to the top.

Angkor, Siem Reap, Cambodia

The capital of the Khmer Empire from the ninth century until about the fifteenth century was the city of Angkor. Angkor encompassed an area larger than 400 square miles. For its estimated 750,000 residents, the city constructed a network of canals, reservoirs, dykes, and basins using local water resources. Researchers and archaeologists are still unsure of the city's demise.

Not so much "discovered" as revived, Angkor. Francois Mouhot, a French explorer, discovered Angkor in 1859, yet the area was still somewhat used and known by the inhabitants. However, the French, who ruled over Cambodia for the majority of the 20th century, established a commission to rehabilitate the monument in the 1900s after years of war, earthquakes, and overgrown vegetation had caused it to deteriorate.

Angkor Wat, one of the biggest temples in the world, is located in Angkor, which was designated a UNESCO World Heritage Site in 1992. In 2019 there were 2.2 million foreign visitors to Angkor, and in 2022 there will be over 280,000.

The Great Sphinx of Giza, Egypt

The Great Sphinx of Giza, according to archaeologists, was constructed approximately 2540 BC. However, it is still unknown to researchers who constructed the building and why. Due of its proximity to the Giza pyramids, the Sphinx is believed to be related to them. Researchers don't yet know who ordered the Sphinx to be created or how it relates to the pyramids.

At the fall of the Old Kingdom in Egypt in 2181 BC, the Sphinx was left unattended and exposed to the elements. For years following its abandonment, all that Egyptians and tourists could see of the Sphinx was its head. Selim Hassan, an Egyptian archaeologist, didn't begin excavating the remaining portions of the Sphinx until 1930, despite numerous attempts.

The Sphinx is one of the biggest and oldest colossal sculptures in the world, at 66 feet tall and 240 feet long. The Sphinx continues to erode due to wind, humidity, and pollution despite restoration and preservation efforts.

Borobudur Temple, Kedu Valley, Indonesia

The largest Buddhist temple in the entire world is the Borobudur temple, which dates back to roughly the year 800. The temple features 500 Buddha statues at its peak, and the ascent to it is lined with 3,000 sculptures that depict Buddha's teachings.

Unknown reasons led to the temple's abandonment in the 1500s, leaving the location in decay as time and nature took their course. The British Governor of Java requested that the temple be excavated in the nineteenth century. Stones, statues, and other components of the temple were stolen in order to be used in construction or for personal collections as a result of the excavation.

In 1968, Borobudur underwent one of the "ambitious international preservation projects ever attempted" and was inscribed on the UNESCO World Heritage List. The statues in the temple were cleaned, and drainage systems were put in to stop erosion.

The Great Temple of Abu Simbel, Aswan, Egypt

In the thirteenth century BC, King Ramses II had the Abu Simbel Temple constructed in his honor. Ramses is depicted in four statues at the front of the temple, with smaller statues of his wife and kids at his feet. The interior of the temple is filled with pictures showing Ramses vanquishing adversaries, in command of his army, and, at the conclusion of his life, joining the gods.

In 1813, Swiss adventurer Jean-Louis Burckhardt rediscovered the temple. Only one of the four Ramses sculptures' heads was visible above the sand when the temple was found. The temple had been sufficiently excavated by 1817 to allow access.

Plans to dam the Nile River put the temple in jeopardy in 1959. The valley where Abu Simbel was located will flood due to the dam. In only its 14th year, UNESCO made the decision to move the complete temple.

By bringing together hydrologists, archaeologists, engineers, and architects, UNESCO completed the temple's relocation in 1968 and set it up where it is now.