3,000 yearsClick to see full answer. Also question is, how old is Cuzco?3,000 years oldLikewise, why is Cusco famous? Former capital city of the Incas, Cusco is the oldest continuously inhabited city in the Americas and a UNESCO World Heritage Site. The ruins of the old Inca city became the foundation for the Spanish architecture you see today, and many of the stone walls that line the streets were built by the Incas. Beside above, when was Cuzco founded? 1200 AD Why was Cuzco abandoned?After Tupac Amaru, the last rebel Inca, was captured, Machu Picchu was abandoned as there was no reason to stay there. It is said that the construction of the citadel was actually during the height of the Inca Wiraqocha, eighth king of Cusco.