Part 2/9:
While the iconic structures of Machu Picchu are astonishing, much remains hidden beneath its surface. Modern exploration techniques allow experts to delve into what lies beneath and around this ancient city, revealing long-forgotten secrets of Inca engineering and urban planning. Some estimates suggest that a staggering 60% of the city is underground, representing a monumental feat of civil engineering overcoming natural threats, and prompting awe at the Incas' ability to adapt to their challenging environment.