Final answer:
The Incan Empire faced the significant challenge of the geographic terrain of the Andes Mountains, which led to the creation of an advanced network of roads and bridges to connect its territory.
Step-by-step explanation:
One significant obstacle that the Incan Empire had to overcome was the challenging geographic terrain of the Andes Mountains. This hostile environment, composed of steep slopes, high peaks, and varied climates, mandated the construction of an extensive and technologically sophisticated network of roads and bridges.
Notably, their road system covered an extraordinary distance, roughly equivalent to the Earth's circumference, and included a diverse range of roads such as straight passages, winding staircases, and bridges made of various materials to facilitate movement and communication across their vast empire.
The Inca built monumental buildings, irrigated terraces, and expanded their empire that included parts of modern-day countries such as Peru, Ecuador, Bolivia, Argentina, and Chile. The road network was a critical achievement because it enabled the fast movement of armies, the transportation of goods to imperial storehouses, and the administration of this immense territory. However, the geographic barriers themselves posed a constant challenge to the empire's connectivity, economic stability, and defense.