A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface. Volcanoes vary quite a bit in their structure – some are cracks in the earth’s crust where lava erupts, and some are domes, shields, or mountain-like structures with a crater at the summit.
Machu Picchu (1460-1470). In the 15th century, the Incan Emperor Pachacútec built a city in the clouds on the mountain known as Machu Picchu (“old mountain”). It is located 2,430 metres (7,970 ft) above sea level. It is situated on a mountain ridge above the Urubamba Valley in Peru. This extraordinary settlement lies halfway up the Andes Plateau, deep in the Amazon jungle and above the Urubamba River. It was probably abandoned by the Incas because of a smallpox outbreak and, after the Spanish defeated the Incan Empire, the city remained ‘lost’ for over three centuries. It was rediscovered by Hiram Bingham in 1911.