Once a famous piece of art has cemented itself in history, it can be hard to imagine that the work started as nothing but an idea. Artists often prepare sketches, models, or drafts before the ultimate work. Scroll to compare conceptual drawings with the final product.

Far from the ornately gilded finished piece, this pencil drawing of The Kiss shows the remarkable simplicity behind one of Klimt's most acclaimed works.

The finished painting, appearing courtesy of the Belvedere in Vienna, was created at the peak of Klimt's 'Golden Period' around 1908. Scroll back and forth to compare the early draft with this one!

This sketch, which appears in a letter to Paul Gauguin, is one of the earliest iterations of van Gogh's portrayal of his bedroom at The Yellow House in Arles, France. The artist produced multiple versions of the piece between 1888 and 1889.

This version, the third and final painting of his bedroom, is currently on display at the Musée d’Orsay, Paris. In addition to subtle differences in color, this version is somewhat smaller than the others, and features updated artwork on the walls.

In 2007, Korean artist Nam Kyung-min created this gargantuan oil painting inspired by The Bedroom. In a nod to van Gogh's decorations, she's recreated several of his other artworks around the room. See if you can identify them all!

Danish sculptor Bertel Thorvaldsen produced this series of sketches to prepare to sculpt the mythical lovers. All the poses tell the story of the intimacy, but only one became set in stone. See if you can guess which drawing turned into the completed piece!

The lovers are on display now in Thorvaldsens Museum in Denmark. Thorvaldsen completed the piece in the first decade of the 1800s. Contrast this lifelike masterpiece with the unembellished drawings which preceded it. 

This illustration of Cupid and Psyche intertwined and facing forward went on to be the model for the ultimate sculpture. Is this the sketch you guessed?

For a change of pace, first look at this unrestrained sketch by Frank Gehry, then try to guess what the final product is. Hint: It is much larger in scale than the other works.

Did you guess that it became the Walt Disney Concert Hall in Los Angeles, California? The venue was conceptualized in 1987, but wasn't open until 2003! Below, you can click to examine the building in 360º using Street View.

Kara Walker's 2014 installation A Subtlety was powerful, poingant, and remarkable in its scope. But even it began as a series of simple sketches.

The installation took place in a disused sugar factory in Brooklyn, New York. The enormous sphinx at the center was encircled by smaller but equally powerful pieces. Watch the video below to see the artist discuss the exhibit and learn how it was created.

Some museums have such winding corridors and vast collections that you could spend days there and still not see it all! Scroll on and use click-and-drag to explore 10 massive museums. Be careful you don't get lost!

By size, The Louvre, in Paris, France is the largest museum on Earth, with nearly 73,000 square metres of exhibition space. By reputation, it's also one of the best and holds works from antiquity to the 19th Century, including the world-famous Venus de Milo and the Mona Lisa.

In terms of size, The State Hermitage Museum in Saint Petersburg comes in second place. However, this art gallery, the first in Russia and opened to the public by Tsar Nicholas I, holds the largest collection of paintings anywhere on Earth.

In North America, the Metropolitan Museum of Art in New York can boast the largest floor space of any single institution, as well as two million objects in their collection. The Met, as it's often known, is one of the most fascinating museums to spend a day exploring.

The Vatican City is the smallest sovereign state in the world, with a population of around 800 people, but it's home to one of the world's largest museums, which displays work from the immense art collection of the Catholic Church, built by the popes over many centuries.

Inside the National Museum of Anthropology in Mexico City, you'll find a wealth of artefacts representing the thousands of years of pre-Columbian history of the Americas. Including the  Aztec Stone of the Sun calender and Xochipilli statue.

Set amongst the peaceful surroundings of Ueno Park, the Tokyo National Museum is the oldest and largest national museum in Japan. The collection focuses on ancient and medieval Japanese art, as well as works that travelled along the Silk Road, connecting Europe to East Asia.

The National Museum of Korea brings together millennia of Korean history, life, and arts, from hand axes of the Paleolithic period, to celadons of the Goryeo dynasty, and modern photography. And when you've seen everything, why not take a walk in the museum's parkland?

The Victoria and Albert Museum has helped generations of designers master their crafts, with a little help from its huge collection of sketches, plaster casts, and genuine artefacts. Spend a day here and lose yourself amongst the sculptures of the famous Cast Courts.

A treasure-trove awaits you at the British Museum, dive into the Saxon hoard of Sutton Hoo and take an edifying adventure through the Egyptian galleries. The museum is one of the oldest in the world, and one of the largest and most comprehensive in history.

In 1855, Berlin's Neues Museum opened to the public, it was originally built as an extension to the Altes Museum, just over the road. Though it was destroyed in the Second World War, it was rebuilt and reopened in 2009, ready to welcome millions more to its huge halls.