What mountain range created formidable obstacles for Inca road builders?

The Andes mountain range created formidable obstacles for Inca road builders. Stretching along the western coast of South America, the Andes are characterized by steep peaks, deep valleys, and varying altitudes, which posed significant challenges for construction and transportation. Despite these difficulties, the Incas engineered an extensive network of roads that connected their vast empire, showcasing their remarkable ingenuity and adaptability in overcoming the natural landscape.