Cradled high up in the Andes Mountains, the Incan city of Machu Picchu is among the most iconic ancient ruins in the world and one of the most popular tourist attractions in South America.

The UNESCO World Heritage Site dates to the height of the Inca Empire, when the city was built as a seasonal residence for the Empire's royal family and religious elites. Though the site is only about 80 kilometers from the Inca capital of Cuzco, Spanish conquistadors never discovered Machu Picchu, which escaped the destruction that befell many other Incan cities during the 16th and 17th centuries. For unknown reasons, the site was abandoned shortly after the fall of Cuzco and was swallowed up by the jungle. Farmers in the region were aware of the ruins for generations and kept the site a local secret until a young Quecha boy led Hiram Bingham to "discover" the ruins in 1911.

Called "The Lost City of the Incas," Machu Picchu sits at a height of over 2,300 meters, on the summit of a steep peak in the cloud forest of southern Peru. Since Bingham's first major effort to excavate and restore the site, hundreds of buildings, roads, stairways and terraces have been discovered. Construction on the site is thought to have begun around 1450. There is evidence that at its peak the city housed as many as several thousand people and contained enough arable land to make and fresh water to remain self-sufficient. Despite the Machu Picchu's grand size and splendor, it served as a royal retreat for less than a century and was abandoned at some point shortly after the Spanish conquest of Cuzco in 1537.

views of Machu Picchu, Peru

The ruins are divided into two zones, referred to as the urban sector and the agricultural sector. The urban sector is composed of dense housing blocks and several buildings that appear to be of religious importance. Prominent among these are Intihuatana, the Temple of the Sun, and the Room of the Three Windows. Built of stone quarried on site, Machu Picchu's buildings are made of blocks so finely carved and placed that they retain their structural integrity today, all without the use of mortar. In the agricultural sector, several terraced fields where the lower class cultivated local vegetables and reared livestock remain.

inside the train to Machu Picchu from Cusco

Today, most people get to Machu Picchu by train from Cuzco which carves its way through the awe-inspiring Sacred Valley. Trains from Cuzco arrive at Aguas Calientes, a small town of at the foot of the mountain on which Machu Picchu sits. Busses from Aguas Calientes shuttle visitors up to the ruins, or for those who like a little action, a switchback trail crossed by foot provides stunning views across the Sacred Valley. The most adventurous souls hike the famed "Inca Trail", a restored cobblestone roadway that connects Machu Picchu to Cuzco. Hiking along the historic trail is a four-day journey but the views and experiences are ones that will not be soon forgotten. At the height of the Inca Empire, roads such as this ran some 5,000 km, from modern day Quito, Ecuador to northern Argentina.

scenes from the Inca Trail, Machu Picchu, Peru

Visitors to Machu Picchu will want to spend at least a full day at the site in order to fully take in the spectacular vistas of the restored ruins that are even more impressive in person than in photographs. For a stunning bird's eye view of Machu Picchu, scramble up the peak of Wayna Picchu, the "nose" visible behind the ruins in many photos of the architectural wonder.

Machu PIcchu, Peru

Tourism to Machu Picchu has not been without a few dilemmas. In 2011, the Peruvian responded to concerns about the deteriorative effects of tourism to the site by setting daily entrance limits and limiting access to the Inca Trail. Because of the new visitation restrictions it is strongly recommended that travelers obtain entrance passes as far in advance as possible for the site as tourists without passes may have difficult obtaining tickets at the gate.