While fortifications have been built in Japan since the 8th century, many of those that remain today, such as Inuyama Castle in Aichi, date to the Heian Period (794–1185 CE). This era of Japanese history saw the rise of local lords and of the samurai warrior class.

The familiar style of tall stone and wooden keeps known as tenshu were developed in the Sengoku period (1467–1603 CE). Originally, these were purely practical structures, designed to be used by threatened daimyō, or feudal lords, in the vicious civil wars of the era.

Over time, these temporary military structures became permanent homes and acted as palaces. They became increasingly elaborate and decorated with ornamentation as the owners sought to show off their keen aesthetic sense as much as their military prowess.

Standing on the summit of Mount Kinkazan, Gifu Castle presents an imposing image, and it was famed as a stronghold. But looks can be deceiving. In the 16th century the castle was captured by just 16 men led by the samurai Takenaka Shigeharu.

Many castles continued to be used right up until the twentieth century, and some even played a part in the Second World War. The ruins of Zakimi Castle were turned into a gun emplacement by the Japanese army, and following the war, it became a US army radar station.

Sadly, many other castles were utterly ruined. Ōgaki Castle survived the Battle of Sekigahara in 1600, but in 1945 the entire castle was destroyed by American bombing raids. The castle tenshu that stands today was rebuilt in concrete in 1959 to house a museum.

Himeji Castle is one of the few genuine historic artefacts. This castle has stood 700 years, surviving all wars and earthquakes that demolished many other structures. It is considered alongside Matsumoto Castle and Kumamoto Castle as one of the country's premier fortresses.

Many artists prefer to stay behind the canvas or camera, but these eminent artists didn't shy away from portraiture. Scroll to see painted portraits side-by-side with photographs.

Pierre-Auguste Renoir was a celebrated painter who lived from 1841 to 1919. In 1876, the French Impressionist captured himself in oil surrounded by hazy, overlapping brushstrokes. This piece hangs in the Harvard Art Museum.

During his later years, Renoir became stricken with arthritis, but continued to paint. He's shown painting outdoors here with a brush tied to his hand. This photograph is part of the LIFE Photo Collection

One of Mexican artist Frida Kahlo's most frequent subjects was herself. This 1954 piece, Marxism Will Give Health to the Ill, appears at the Museo Frida Kahlo in Coyoacán, Mexico.

This photo by Bernard Silberstein was taken around 1940. Kahlo is seated in front of a plain backdrop, adorned in traditional garments and a headdress of bougainvillea and white rose. Both this photo and the previous painting appear courtesy of the Museo Frida Kahlo.

In 1931, Kahlo also painted herself alongside her husband, Diego Rivera. A celebrated painter in his own right, Rivera was renowned for large, colorful frescoes. This piece currently resides at the San Francisco MOMA.

This photograph of Diego Rivera shows the artist seated next to one of the beloved dogs who lived at La Casa Azul with Kahlo and Rivera. This picture also appears courtesy of the Museo Frida Kahlo.

Art can change the nature of a place. The real-world scenes of some of history’s most famous artworks have since become sites of spooky significance. Whether through their association with a dark and mysterious artist, or because of their depiction in a particularly atmospheric image, some landscapes are, for one reason or another, haunted by their aesthetic or historical past.

Few paintings are as famed or as feared as American Gothic (1930). Grant Wood’s rustic portrait is infused with a vague sense of heartland darkness. Generations have felt a strange unease in the ambiguous relationship between the two figures and their horror-movie setting.

The real life Dibble House still stands today in Mt. Vernon, Iowa.    

Edvard Munch’s iconic picture of human despair has become one of history’s most famous paintings. Its plunging perspective and fiery palette gave expression to modern humanity’s anguish and anxiety. 

The intense landscape through which the three figures walk has been identified as a fjord above Oslo, the view being from a road called Valhallveien.

Munch exaggerated the angles of the road to give his painting great drama, but the place is recognizable, and marked in real life by a plaque.                                                 

Gustave Courbet’s Burial at Ornans (1849-50) is set in the rural French town of Ornans where the painter was born. The landscape accurately depicts the craggy, low-Alpine features of the Franche-Comte countryside, and each figure is modelled on a real-life inhabitant of the town. Courbet was inspired to paint this scene after the death of his beloved Grandfather Jean-Antoine Oudot in 1849.

But at the extreme left of the painting, his grandfather himself appears, looking down the length of the casket to the open grave. Is he a ghostly attendant at his own funeral?                                                                                                       

Parts of the sleepy town of Ornans still look much as they would have done during Courbet’s lifetime, and the cliffs of the Via Ferrata, overlooking the scene from the top of Roche du Mont, are instantly recognizable.     

As a journalistic painter reporting from the front-line of two world wars, Paul Nash was exposed to some of history’s grisliest battlegrounds. His response was to paint the landscapes in a surreal tone, the violence enacted on these fields transforming them into horrific, unnatural zones.

He painted The Menin Road (1919) to record the horrors of the Ypres offensives in Belgium.                                                                   

Though it no longer bears the surreal atmosphere of Nash’s painting, Flanders still bears the weight of its violent past. 

Friedrich's landscapes are often heavily contrasted, shadow and light throwing figures into sharp relief. This refines details to simple, powerful shapes, allowing them to function as symbols or allegories.

Here the tendrils of leafless trees give us a haunting, fractured sky.               

The eerie mood that Friedrich captured still hangs over the real-life site.

Great art is able to convey so much more than just colour and form. It can communicate emotions and ideas, tell stories and even challenge and confuse. Not all of this is immediately evident and it can take time and effort to work out the true meaning of any work.    

For the most part, the artist wants the viewer to understand the context and meaning of any painting. But that’s not always the case. Sometimes artists include hidden messages in their work, hiding them away so that only a select few people can understand their true significance.
 
Below we look at five paintings and discover the hidden messages not everybody was supposed to see. 

Vincent Van Gogh, 1888

Painted in 1888, Van Gogh’s classic is one of his most recognizable works. The scene depicts a seemingly ordinary café on a cobbled street. A waiter stands to take an order while patrons sit around leisurely. 

However, scholars have begun to believe the painting features an homage to Leonardo da Vinci. The twelve figures at the back sit beneath what looks like a cross. It also transpires Van Gogh declared a ‘tremendous need for religion’ in a letter to his brother around this time. 

The 12 sit along one side of their tables, like Leonardo's disciples, and a shadowy figure departs the scene like Judas.

Leonardo da Vinci, 1490s

Of course, The Last Supper itself is said to contain hidden messages. As one of the most famous paintings in history, and a deeply important religious work, it's not surprising that people have often looked hard for deeper meanings.

In 2007, an Italian musician claimed to have found a selection of musical notes in the painting, hidden in bread rolls and other table features. When played they create a 40-second composition. It’s not impossible, given that Leonardo was a fine musician himself.

Frida Kahlo, 1929

Not all hidden meanings are meant to be publicly discovered. This is especially true of Kahlo’s El Autobus. What appears to be a simple depiction of Mexican society laid out on a wooden bench at a bus stop may have a more personal tone.

Four years before she painted it, Kahlo had been involved in a bus accident that left a permanent scar. The woman to the right of the picture appears to be Kahlo and the man in the blue overalls apparently bears a striking resemblance to the man who pulled an iron bar from her stomach after the accident.   

L.S. Lowry, 1926

L.S Lowry’s pictures are renowned for depicting working class life in the north west during the early to mid 20th century. His matchstick figures have entered the popular consciousness, even inspiring a song.

However, his pictures are more than just happy matchstick people going about their day. Many contain small scenes of hardship and despair. This is particularly true of 1926’s An Accident which may feature a scene inspired by a local tragedy – giving his works a much deeper social meaning. 

Michelangelo, 1477-1480

One of the great figures of the Renaissance, Michelangelo took years to create his masterpiece on the Sistine Chapel ceiling. However, there may be more on display than simply incredible beauty.

Art historians believe his work contains several hidden anatomical sketches, including an image of the human brain, disguised in the creation scene. This is believed to be a criticism of the Church’s attitudes to the science and discovery that was happening all around.