The lost city of Machu Picchu is discovered

On 24 July 1911, American archaeologist Hiram Bingham gets his first look at Machu Picchu, an ancient Inca settlement in Peru that is now one of the world's top tourist destinations. Tucked away in the rocky countryside northwest of Cuzco, Machu Picchu is believed to have been an estate for an Incan emperor, and was also believed to be of religious significance due to its proximity to ancient sacred sites.

The Incas were believed to have started building Machu Picchu in 1430 AD and completed it around 1460. However, they abandoned it only less than a hundred years after its completion, and researchers hypothesise that its inhabitants were wiped out by smallpox before the Spanish arrived. Machu Picchu is one of only a few Inca sites that was not found and plundered by the Spanish conquistadores on their arrival in the sixteenth century.

For hundreds of years afterwards, its existence was a secret known only to the peasants living in the region. That all changed in the summer of 1911, when Bingham arrived with a small team of explorers to search for the famous "lost" cities of the Incas. Travelling on foot and by mule, Bingham and his team made their way from Cuzco into the Urubamba Valley, where a local farmer told them of some ruins located at the top of a nearby mountain.

The farmer called the mountain Machu Picchu, which meant "Old Peak" in the native Quechua language. The next day – 24 July – after a tough climb to the mountain's ridge in cold and drizzly weather, Bingham met a small group of peasants who showed him the rest of the way. Led by an 11-year-old boy, Bingham got his first glimpse of the intricate network of stone terraces marking the entrance to Machu Picchu.

The excited Bingham spread the word about his discovery in a best-selling book, sending hordes of eager tourists flocking to Peru to follow in his footsteps up the Inca trail. The site received more publicity when the National Geographic Magazine devoted its entire April 1913 issue to Machu Picchu. Machu Picchu was declared a UNESCO World Heritage Site in 1983. The site itself stretches an impressive five miles, with over 3,000 stone steps linking its many different levels.

Today, more than 300,000 people tramp through Machu Picchu every year, braving crowds and landslides to see the sun set over the towering stone monuments of the "Sacred City" and marvel at the mysterious splendour of one of the world's most famous man-made wonders. However, tourism and its accompanying infrastructure impose a physical burden on the ruins, and UNESCO is considering placing Machu Picchu on its list of endangered World Heritage Sites.