The Inca civilization lived high up in the Andes of Peru. They started out in the thirteenth century in the town of Cuzco, and expanded their empire over parts of Ecuador, Bolivia, Argentina, and Chile. Their architecture was made to fit the mountain scenery. They built their cities up in the hills, but had elaborate town centers with many temples. One temple in Cuzco had smooth curved walls.
The Incas also built fortresses and walls. One such fortress is Saqsaywaman. It was built to protect the capital city of Cuzco, and was also used for religious and royal purposes. Part of this fortress was a wall that stretched more that 1500 feet. Another fortress, and the most well known Inca city is Machu Picchu. It is said that it was built as the sanctuary for the Inca king Mancho II from the invading Spaniards. It had plazas, sacred temples, and houses all over on the steep mountain side. There are remains of stairways, and terraced gardens.
The Incas also made roads to connect their cities. The longest one, stretching on for 3,250 miles, is the Inca Royal Road in the Andes. They even built suspension bridges over gorges.
All of this was destroyed when the Spanish conquistadors came through.