Have you ever wondered what famous cities used to look like before our time? The last 100 years or so have seen incredibly fast advancements in architecture, city planning, engineering and technology, so it's no surprise that urban areas are rapidly changing too. Here we journey back in time to reveal historic images of the world's greatest cities, and to find out what's changed and what hasn't.

Captured from Greenwich Park sometime between 1945 and 1965, the Old Royal Naval College and Queen's House dominate the landscape here while, directly opposite, the view of the Thames' north bank is characterised by countless factory chimneys. Canary Wharf, alongside the Isle of Dogs, Limehouse and Poplar, were among the busiest docks in the world. After the 1960s, the port industry here declined and the docks closed completely by 1980.

In the 21st century, Canary Wharf looks completely different. Long gone are the factory chimneys, replaced by ultra-modern skyscrapers, tower blocks and cranes building yet more high-rises. While the Old Royal Naval College and Queen's House remain as they were, the old docks have been reimagined as one of London's financial centres and a significant business district. The development here is so rapid that 76 new skyscrapers were finished in central London in 2019 alone.

Once the focal point of Las Vegas, Fremont Street is pictured here in 1953. Back then, Golden Nugget (one of the oldest casinos still open in the city) and its huge sign were a dazzling symbol of Sin City. The area, also home to The Hotel Apache, El Cortez and The Mint, became known as the Glitter Gulch, thanks to all the tall neon signs looming over the narrow street. However, soon after, a development boom kickstarted the rise of the Las Vegas Strip, and today Fremont Street looks a lot different...

Gone is the Golden Nugget's towering sign (though the casino is still open) and the tightly packed hotels from 1953. The street's appearance changed completely in 1995 when the new and improved Fremont Street Experience – a pedestrian mall with attractions, casinos and concert stages – was unveiled. Occupying five blocks, including the Glitter Gulch, the street was closed to traffic and covered with a massive light canopy in a bid to revive Downtown. One of the few things that's survived to this day is Vegas Vic: a neon sign portraying a cowboy. Take a look back at the history of Las Vegas here.

Originally built to house the British colonial administration in Kuala Lumpur, the Government Offices building, as it was then known, was opened in 1897, and is photographed here in the early 1900s. Located in the city centre, the ornate pile was the grandest in Kuala Lumpur at the time – the city was still in its early days, having only been founded in 1857.

Today, Malaysia's capital casts a vastly different figure. After gaining independence from the British first, and then the Japanese, Malaysia's growth was quick, especially starting from the early 1990s. Soon famous additions like the Petronas Towers and Kuala Lumpur Tower (both seen in the background here) defined the city's skyline. The Government Offices have since been renamed as the Sultan Abdul Samad Building, and the structure currently houses the Ministry of Communications and Multimedia and the Ministry of Tourism and Culture of Malaysia. 

Captured from Twin Peaks in 1947, the San Francisco cityscape is almost unrecognisable, if not for the Oakland Bay Bridge, finished just around 10 years prior to this photo. While some high-rises had already appeared in the city's Financial District, much of the city changed in the coming decades, as the urban planning projects of the 1950s and the 1960s focused on widespread redevelopment of neighbourhoods and the construction of new freeways.

Some 70 years later, San Francisco's growth is obvious. While some landmarks, like the tree-lined Market Street and San Francisco City Hall can still be made out, others, like the Oakland Bay Bridge, are almost completely obstructed by the new developments in the Financial District, The East Cut and Rincon Hill. Much of the city's growth has been fuelled by the dot-com boom in the 1990s, and the social media boom since the mid-2000s, driving gentrification and a second wave of high-rise developments. Love this? Here are incredible images of the world's tourist attractions under construction.

Running along the bank of the Huangpu River, this famous boulevard, also known as the Bund, houses many of Shanghai's more European-style buildings, including what was once the Shanghai Bank (the large domed building) and the North China Daily News Building (the building with two small domes next to the flagpole). Captured here in 1927, the waterfront still had several docks for small boats and apart from the few grand buildings along the Bund, the rest of the city's skyline is low.

Almost a century later, it's a vastly different sight. While some of the buildings from 1927 are still there, like the old Shanghai Bank building and the North China Daily News Building (now AIA Building), the rest of the city has changed immensely. The streets behind the Bund are defined by high-rises and the docks have been turned into an attractive waterfront promenade.

Consecrated in the 15th century, the Berlin Cathedral, pictured here circa 1890, has had multiple iterations. A significant Berlin landmark both then and now, it was badly damaged in the Second World War and its reconstruction didn't start until 1975. Around the time when this photo was taken, Berlin had become the capital of the newly founded German Empire, which inspired rapid growth and expansion in the city. This, combined with the damage of two World Wars, means it's unsurprising that the city's face has changed so dramatically...

The reconstructed cathedral today is notably different to its predecessor – gone are the ornate details on the central dome and the façade itself. As the cathedral fell into East Berlin after the division of Germany, the communist government also demanded the removal of as many crosses as possible. Today, it's one of Berlin's best-known landmarks along with the Berlin Fernsehturm (Berlin TV Tower) in the background. The latter has become the city skyline's most recognisable feature.

Established in the early 18th century as a fishing village, Dubai has come a long way. Even before the discovery of oil, Dubai played an important part as a trade location due to its proximity to Iran. After the detection of oil in the region in the 1960s, Dubai's growth has been non-stop. Photographed here in 2003 Dubai Marina is in its early days: an artificial canal city stretching along the Persian Gulf shoreline, it's now a district of Dubai.

Staggeringly, this photo of Dubai Marina was taken just over 15 years later – a snapshot of Dubai's interstellar growth and development. Only the first phase of the Dubai Marina development has been officially finished and when it's complete, it's expected to house more than 120,000 people in residential towers and villas.

A city with a long and illustrious history, Florence needs no introductions. Its famous Ponte Vecchio is captured here in 1893, just 22 years after Rome replaced the city as the capital of the Kingdom of Italy. During the Second World War the city was under a year-long German occupation and as the British troops closed in, the Germans had plans to destroy all of the bridges along the Arno river in 1944, including Ponte Vecchio. Thankfully, a consul managed to convince a German general to spare the bridge due to its historic value.

While some cities continue to change face with every passing decade, there's something very comforting about seeing Florence today almost exactly as it was back in 1893. A UNESCO World Heritage Site, much of Florence's historic centre is preserved and remains largely unchanged, so the Ponte Vecchio we see today is almost the same as it was back in the 16th century when the Medici family walked the Vasari Corridor above it.

A hugely important city, Cairo has a history stretching as far back as Ancient Egypt. While much has changed in the city over time, one of Cairo's most significant monuments has stood the test of time: the Mosque-Madrassa of Sultan Hassan. Built in the mid-14th century, it's photographed here circa 1930.

Pictured here almost a century later, much of the city has changed. Several high-rises dominate the skyline in the background, but the historic structures themselves appear as if not a day has gone by. Today, Cairo has a population of around nine million and its footprint on the map has spread as far as the pyramids, already bordering the Giza Necropolis complex.

Australia's most populous city, Sydney has a tumultuous history, marred by countless conflicts, leading up to the 19th century when the situation stabilised and the city established itself as a major cultural and financial centre in Australia. Although the Great Depression hit the country hard, the iconic Sydney Harbour Bridge was opened in May 1932. After the war, the city boomed and new industries grew, inspiring widespread development. But, captured here in 1955, Sydney Harbour is still missing a key landmark that was opened in 1973...

This more recent image reveals the view we're so used to seeing, and includes the iconic Sydney Opera House. But it's not just the addition of the Opera House that's different. The city itself has grown in size and Sydney's Central Business District is now defined by skyscrapers and high-rises. There have also been changes on the other side of the harbour, where Luna Park Sydney, an amusement and entertainment park, has sprung up. Now take a look at what the world's tourist attractions could have looked like.

Very few locations in New York City have been through such drastic changes as Times Square. Grown out of a tiny hamlet known for carriage-making, the area developed into the centre of New York's horse carriage industry in the late 1800s. It was named Longacre Square after Long Acre in London, and it was here that William Henry Vanderbilt ran the American Horse Exchange. As plans to build a subway station here emerged, the area was renamed Times Square. Here, it's pictured around 1900, facing south to Broadway on the left and 7th Avenue on the right.

Since the Great Depression and both World Wars, Times Square has grown dramatically, and has become a hub for theatres, dance halls and upscale hotels, as well as the centre of New York's New Year celebrations. It's also a major tourist attraction, and is where Good Morning America is broadcast live from ABC's Time's Square Studios. Now take a look at America's most historic attractions in their heyday.

Arc de Triomphe, officially called Arc de Triomphe de l’Étoile, is one of the French capital's most famous sights, commemorating the French soldiers who fought and died in the French Revolutionary and Napoleonic Wars. Snapped in the first half of the 1900s, around 100 years after the landmark was finished, this aerial photo also gives a good glimpse of what the city used to look like, including the tree-lined avenues that surround it.

A much more recent photo reveals that the leafy avenues and typically Parisian buildings with French windows are still very much in place. In fact, unlike many other places in Paris, this area seems to have changed very little. One small change is the star shape adorning the roundabout encircling the Arc de Triomphe. A 12-point star pointing towards each of the 12 avenues that form the junction, it's a nod to the Place de Charles de Gaulle's previous name: Place de l'Étoile, with étoile meaning star.

No work by legendary architect Antoni Gaudí is more famous or impressive than his plan for Sagrada Familia. Work on the landmark began in 1882 (originally under the watch of Spanish architect Francisco de Paula del Villar) and it’s pictured here some 60 years later, circa 1940.

The difference 80 years of construction can achieve is quite staggering. Sagrada Familia today looks as if it's an entirely different building. In 2015 it was announced that the construction is 70% complete and most of the church's structure is set to be complete by 2026, the centennial of Gaudí's death. One element that is still to be added is the immense central Christ steeple. It's estimated that the basilica will finally be finished by 2032. Now check out some of the world's most amazing unfinished landmarks.