At its maximum extent, around 500 years ago, what countries marked the northern and southernmost limits of the Inca empire?

The Inca Empire, known to its people as Tawantinsuyu, was a true marvel of engineering and administration. At its peak in the early 16th century, it was the largest empire in the pre-Columbian Americas, stretching over 2,500 miles along the formidable Andes Mountains. The northernmost boundary was established at the Ancasmayo River, which today runs along the border of modern-day Ecuador and Colombia. In the south, Inca control extended all the way to the Maule River in what is now central Chile.

This incredible expansion occurred relatively quickly, mostly within the century leading up to the Spanish arrival. From their capital city of Cuzco in Peru, a series of powerful emperors rapidly conquered neighboring peoples and territories. To manage this long, narrow domain, the Inca developed a sophisticated administrative system and built the Qhapaq Ñan, an extensive network (Review) of roads and bridges that connected the far-flung corners of their empire.

This vast territory encompassed an incredible diversity of landscapes, from arid coastal deserts to the world's highest tropical mountains and the fringes of the Amazon rainforest. This geographic reach, from the equatorial north down to the more temperate south, allowed the Inca to command a stunning variety of resources and peoples, cementing their power across a huge swath of South America.