The Inca Empire was a powerful civilization that united tribes in the Andes mountains through a common language and religion. They built an extensive network of stone roads over 2,500 miles long to connect coastal areas to the highlands. Some of these Inca trails are still used today by local farmers or form the basis for modern roads. One such trail is the Inca Trail, a well-preserved 4-day walk that connects the lost city of Machu Picchu to Cusco through varying landscapes like high altitude passes and cloud forests, culminating in views of Machu Picchu from the Sun Gate.