The Inca ruins are remnants of the ancient Inca Empire, which thrived in the Andes Mountains of South America from the 15th to the 16th century. These structures showcase advanced engineering and architectural skills, with many built from precisely cut stones that fit together without mortar. Notable sites include Machu Picchu, a famous citadel, and Sacsayhuamán, known for its massive stone walls. These ruins serve as important archaeological sites, providing insight into the Inca civilization's culture, religion, and daily life. Many ruins are now protected as part of UNESCO World Heritage Sites, attracting tourists and researchers interested in ancient history.