The final day of the hike took us downward nearing our starting altitude, and finally ending at the lost city of Machu Picchu. After many snapshots and a brief orientation, we took the bus to Aguas Calientes to clean up and rest.

Machu Picchu - or "Old City" - was built around 1460, but then abondoned during the Spanish conquest. The city remained unknown to the outside world until it was scientifically discovered by Hiram Bingham in 1911. It was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO world heritage site in 1983.

We returned to Machu Picchu in the morning for a stone-by-stone tour of the ancient city before the crowds arrived, including an optional climb of neighbouring Wayna Picchu. Returning to Aguas Calientes, we took the train out of the district of Machu Picchu back to Cusco.

The central buildings of Machu Picchu are constructed using the classic Inca architectural style of polished dry-stone walls. Blocks of stone are cut to fit perfectly together without the use of mortar. Some junctions of stone are so perfect that not even a knife blade can fit between the stones.

Day eleven was our free day in Cusco. We visited several museums and enjoyed the atmosphere of the city. In the evening, we shared our farewell dinner with our guide.

Qoricancha was the most important temple in the Inca Empire, dedicated to Inti, the Sun god. The temple was littered with gold, covering walls and floors, and dotting the property with statues. The Church of Santo Domingo was built on its remains, but when earthquakes severely damaged the church, the original Inca walls remained intact due to the sophisticated stone masonry of its construction.

A varied commute took us into Puerto Maldonaldo and Sandoval Lake in the Amazon jungle. A night-walk give us a personal introduction to the nocturnal jungle life in the area.

The Amazon River is the largest river in the world by volume, and second longest, only slightly shorter than the Nile. It's drainage basin, the world's largest, accounts for one fifth of the world's total river flow. The most distant source of the Amazon is a glacial stream at Nevado Mismi, in the Peruvian Andes, and empties about 6400km away into the Atlantic Ocean on the north east coast of Brazil.