Archaeologists in Peru have discovered a hidden Inca tunnel network known as the Chinkana beneath the city of Cusco. The extensive underground passages stretch over 1,750 meters and connect several significant sites, including the Temple of the Sun and the fortress of Sacsayhuamán. The discovery was made based on historical accounts and guidance from historian Manuel Chávez Ballón. The researchers used sound tests and advanced technology, including ground-penetrating radar, to map out the tunnel system. The Chinkana tunnel network consists of enormous trenches lined with stone walls, ceilings, and carved stone beams.