The Hagia Sophia is a magnificent architectural work that served as a landmark for the Byzantine and Ottoman Empires. The Hagia Sophia, first a Christian church, then a mosque for Muslims, and finally a museum, has always been a historical treasure. Several civilizations have called Istanbul home for millennia. The city now reflects the characteristics of two distinct cultures, and the Hagia Sophia is unquestionably a wonderful blend, with both Ottoman and Byzantine influences visible beneath one massive dome.

The first construction of the structure was carried out by Emperor Constantine the Great (306-337). However, the ancient cathedral has been rebuilt numerous times due to various reasons, such as being destroyed in riots and earthquakes. Despite this, Hagia Sophia is regarded as one of the world's great structures. And as if that weren't cool enough, the structure can also be seen in the first few minutes of the newest Bond movie, Skyfall.

The Hagia Sophia in Istanbul, Turkey, was designed by Isidore of Miletus and Anthemius of Tralles and completed in 537 AD. It was the world's largest building at the time and is said to have 'changed the history of architecture due to its massive central dome. Originally a Greek Orthodox cathedral, it was converted into a mosque during the Ottoman Empire and is now a museum. The best-preserved example of Byzantine architecture, it was the largest cathedral in the world for 1000 years until the Spanish, in a fit of jealousy millennia in the making, built a bigger one.

It has grown to be one of the most significant cultural and architectural landmarks in the entire world, attracting not only tourists but also researchers, academics, engineers, artists, and archaeologists. The structure was made as a place of worship, and it has fulfilled that purpose for many years.

Completed: 537 AD
Function: Mosque
Architect: Isidore of Miletus (442 AD – 537 AD)
Location: Istanbul, Turkey

Despite not being the tallest, it is unquestionably one of the most stunning and recognizable structures in the world. The Taj Mahal, also known as the Crown Palace, is one of the modern Seven Wonders of the World. It was constructed in memory of Mumtaz Mahal, the Mughal Emperor Shah Jahan's wife, who passed away in 1631 while giving birth to the couple's 14th child.

This remarkable monument's geometry, structural grandeur, exquisite calligraphy, inlaid diamonds, and gorgeous landscaping astound visitors. The Taj Mahal was more than a wedding memorial; it was Shan Jahan's declaration of eternal love to his late sweetheart. In his grief, Shah Jahan channeled his emotions into constructing an ornate and expensive mausoleum that would put all others to shame. It was also notable for being the first large mausoleum dedicated to a woman.

One of the best examples of Mughal architecture, which combines Persian, Turkish, and Indian design elements, is the Taj Mahal. Although Shah Jahan, who had a passion for design, is thought to have worked directly on the plans, there is no known main architect for the Taj Mahal. The 22-year construction process resulted in a magnificent structure and narrative that annually draws millions of tourists. The Iconic Building underwent construction from 1632 until 1648. It took an additional five years to complete the surrounding structures and gardens.

Completed: 1643
Function: Tomb
Architect: Ustad Ahmad Lahauri (1580 -1649)
Location: Agra, India

The construction of the Colosseum, one of Rome's most iconic structures, began in 72BC with Emperor Vespasian and was completed by his heir Titus. The largest amphitheater ever built, it could accommodate up to 80,000 spectators for gladiatorial contests, theater, and public spectacles. To simulate sea battles, the floor could even be flooded. The architects' designs for getting large crowds in and out quickly are still used as the foundation for modern stadiums. It's a must-see for fans of ancient Rome and Russell Crowe alike, as it's one of the most famous ancient Roman structures.

The iconic building, constructed of concrete and stone, began construction around 72AD and was completed in 80AD. Many modern-day stadiums have been inspired by the design and shape of the Colosseum. It is now one of the most popular tourist attractions in Rome, attracting thousands of visitors each year.

Completed: AD 80

Function: Amphitheatre

Architect: Vespasian, Titus

Location: Regio III Isis et Serapis, Rome, Italy

The Sydney Opera House in Sydney, Australia, is widely regarded as one of the twentieth century's greatest architectural works. The stunning structure is made up of three interlocking shell groups that house two main performance halls and a restaurant. The Sydney Opera House, a modern architectural masterpiece, has become an iconic symbol of both Sydney and the Australian nation.

Despite not being particularly large or tall, the Sydney Opera House's distinctive architecture is absolutely astounding. The opera house, the hub of Australian culture, is renowned worldwide for its unique design of concrete shells. Despite Melbourne residents' insistence that this landmark is unimportant and "looks like a bunch of nuns hanging out," the Sydney Opera House is one of the most famous modern structures in the entire world.

The building's construction began in 1958, following a design competition won by Danish architect Jørn Utzon. A concert hall, a drama theater, an opera theater, a studio, the Utzon room, a forecourt, and a recording studio are all part of the structure. There are also five restaurants and obligatory souvenir shops.

Completed: 1973
Function: Performing arts center
Architect: Jørn Utzon
Location: Sydney, Australia

In the past, the emperor was given Heaven's highest authority because it was believed that he was a son of Paradise. As an earthly replica of the celestial Purple Palace or the North Star, the emperor's residence was built facing north with the intention of housing the Celestial Emperor. The name "Forbidden City" refers to the fact that it was obviously forbidden to commoners as a sacred site.

Emperor Yongle usurped the throne from his nephew. He made the decision to move the capital from Nanjing to Beijing in order to bolster his imperial authority and protect his personal safety. As a result, Emperor Yongle gave Kuai Xiang the job of building Beijing's Forbidden City. There are a few side gardens with interesting halls to explore.

The Forbidden City, located in Beijing, is a city within a city. It is not so much a single building as it is a complex that houses nearly a thousand buildings. While most people are familiar with its iconic gates, the complex itself spans 72 hectares and was originally commissioned in the early 15th century by an emperor of the Ming Dynasty. Despite the fact that it took only fourteen years to construct, it has served as the ceremonial and political center of the Chinese government for over 500 years.

Because of the religious and philosophical significance of the complex, its architecture is heavily symbolic, with elements like the inner and outer halls being arranged in groups of three to signify the Qian triangle. The statuettes on the roofs of the buildings indicate their significance with their heavenly implications. The complex used to be a very much-forbidden city, but it is now accessible to the general public, which is fantastic if we can ever travel again.

Completed: 1925
Function: Palace
Architect: Kuai Xiang (1398 – 1481)
Location: Beijing, China

In reality, the most popular tourist destination in Moscow is this garish, candy-colored cathedral. St. Basil’s Cathedral, which is situated just outside the Kremlin gates and designates the geometric center of the city, is shaped to resemble the flame of a bonfire rising into the sky.

Legend has it that the architect of the cathedral was blinded after it was finished in order to prevent another structure of this magnitude from ever being built. It has a distinctive appearance thanks in part to the colorful domes and brilliant redbrick towers. Each dome, which is a part of nine different chapels inside the cathedral, symbolizes the Kazan attack.

The cathedral was built between 1554 and 1560 during the reign of Ivan IV (Ivan the Terrible). Postnik Yakovlev, the building's architect, is little known, but he was clearly a fan of onion domes, sharp spikes, and polygonal towers. The architecture of the cathedral is inspired by Jerusalem architectural styles and has deep religious significance.

When viewed from above, the eight domes that form a circular pattern around the ninth sphere resemble a star. The interior of St Basil's Cathedral is very different from its exterior, with simple decorations and narrow passageways. The cathedral has been damaged by fires, theft, and other occurrences several times throughout its history.

Completed: 1561
Function: Cathedral
Architect: Postnik Yakovlev
Location: Moscow, Russia

Given that every item on the top 10 reasons architects visit Barcelona list begins with "Gaud built it," we suppose this one is a bit of a given, but the Sagrada Familia Basilica stands head and shoulders above the rest. They haven't even bothered to finish the building, so it's not bad. Despite the fact that construction started in 1882, it has taken a long time to reconstruct the plans after they were partially destroyed during the Spanish Civil War. It is hoped that the building will be finished in its entirety by 2026, one hundred years after Gaud's passing.

The Sagrada Familia cathedral, which is in Barcelona, Spain, wows millions of visitors each year with its imposing architecture. It's difficult to imagine this structure as anything other than a cathedral, even though that wasn't its intended use. It has recognizable towers and combines Gothic and Art Nouveau designs. The structure is a testament to how distinctive Gaud's creations are and has grown to be one of Barcelona's top tourist destinations for both professionals and casual visitors.

Completed: After 2026
Style: Gothic Revival and Art Nouveau and Modernista
Function: Church
Architect: Antoni Gaudí
Location: Barcelona, ‎Spain

The Greeks who survived and later won the war decided to leave the ruins on the hill as a reminder of what they had been through after Persian invaders burned the original acropolis to the ground. All of this changed in the fifth century when the then-Athenian General Pericles reasoned that while the idea was admirable, perhaps it would be better to erect a memorial that wasn't quite so offensive. As a result, the most well-known example of ancient Greek architecture exists.

The Acropolis, designed by Ictinus and Callicrates, is made up of several temples. These massive structures loom above the city of Athens, perched atop a high outcrop. The most famous of these is the Parthenon, a massive temple dedicated to the goddess Athena that was built between 447 and 432 BC. The temple held some of the finest examples of Greek sculpture in the form of the temple frieze and metopes, but don't expect to see any of those in Greece, given that the English took them all and aren't particularly eager to return them.

Completed: 432 BC
Function: Temple
Architect: Ictinus and Callicrates
Location: Athens, Greece

For the 1962 World's Fair, the futuristic Space Needle in Seattle, Washington, was constructed. One of the most recognizable structures in the world is the Space Needle in Seattle.

The famous landmark is 184 meters tall and 42 meters wide at its widest point. Edward E Carlson and John Graham, architects, collaborated on the design. It has a rotating restaurant on top called SkyCity, with an absolutely stunning view all around.

Aside from the aesthetics, the structure is built to withstand 200 mph winds and 9.1 magnitude earthquakes, and it also has no less than 25 lightning rods, so as fragile as it may appear, it's a tough one.

Completed: 1961
Function: Observation tower
Architect: John Graham & Company
Location: Seattle, Washington, U.S.

One of Europe's most amazing architectural creations is the Leaning Tower of Pisa. The Leaning Tower of Pisa has a legendary status. It is well-known everywhere, and people all over the world refer to it and its stories. The famous tower in Italy was constructed as a bell tower in the 12th century. The tower is best known for its tilt, which developed during construction when the soft ground on one side was unable to adequately support the weight of the building.

As construction progressed until it was finally finished in 1372, the building's soft foundation began to tilt because it couldn't support the full weight of the structure. The tower is currently 5.5 degrees inclined and completely stable. It also has a well-established reputation.

The tower currently leans at just under 4 degrees due to restoration work done in 2001. It is predicted that the iconic building will crumble within the next 75 to 100 years.

The tower's construction lasted for more than three hundred years, starting in the year 1173. The true identity of the architect who designed the tower has been the subject of much debate; the design was initially credited to artist Bonnano Pisano, but studies have also implicated architect Diotisalvi.

Completed: 1372
Architect: Bonanno Pisano
Style: Romanesque
Height (max): 55.86 m (183 ft 3 in)

Location: Piazza dei Miracoli, Pisa, Italy

Solomon R. Guggenheim Museum, which is located right next to Central Park in New York City, was designed by architect Frank Lloyd Wright and constructed between 1943 and 1959. Most art museums only allow terrible people to say "Is this art?" while inside the building, but at the Guggenheim, it's also possible to say it while standing outside.

The cylinder-shaped building, which has a wider top than the bottom, was intended to serve as a "chapel of the spirit." Its unique ramp gallery ascends from floor level in a long, uninterrupted spiral along the building's exterior walls, coming to an end right beneath the roof skylight. The building underwent significant enlargement and modifications when a nearby tower was finished in 1992, as well as from 2005 to 2008. Rebay envisioned the space as a "temple of the soul," offering a novel viewpoint on the modern components of the collection.

Even before it opened, some critics complained that the design was such a work of art in and of itself that it risked overshadowing the artwork inside, which honestly feels like a pretty good review for Wright's work.

Completed: 1937
Function: Art museum
Architect: Frank Lloyd Wright (1867 – 1959)
Location: Manhattan, New York, United States

We couldn't compile a list of notable structures without mentioning this magnificent Art Deco skyscraper. The Empire State Building, once the tallest structure in the world, had its construction start on St. Patrick's Day 1930, and end just 410 days later.

In no film or television program was it ever finished without showing up on the screen. The Empire State Building, a National Historic Landmark proudly constructed in 1930 and 1931, is the most recognizable symbol of New York.

Due to the Great Depression, the building sat vacant for the next twenty years. The Empire State Building, a timeless monument of the great American city, has seen a lot more in its life. It has survived a plane crash in 1945, shootings in 1997, and more than 30 suicides, but it remains an iconic architectural wonder today.

William F Lamb of the architectural firm Shreve, Lamb, and Harmon designed the iconic building. It was named one of the Seven Wonders of the Modern World by the American Society of Civil Engineers and is recognized around the world as an icon of New York City.

Completed: 1931
Function: Office building; observation decks
Architect: William F Lamb
Location: New York, United States