Machu Picchu, the phenomenal "Lost City of the Incas", sits like a proud lion perched on a high plateau (2,430-metres above sea level) in a tropical mountain forest that is perpetually swathed in ribbons of clouds. The city was built in the 15th century and is a marvel of mortar-free limestone architecture. It is probably the most amazing urban creation of the Inca Empire at its zenith. Although the site was known locally, it was unknown to the outside world until it was "discovered" in 1911 by American historian Hiram Bingham. Board a train or take the multi-day hiking trail but make sure you see the ruins at sunrise.