What Did The Inca Empire Create?

What Did The Inca Empire Create? Pachacuti Inca Yupanqui also focused his efforts on strengthening Cusco, the center of the empire. He expanded Sacsahuaman, the massive fortress that guarded the city, and embarked on an expansive irrigation project by channeling rivers and creating intricate agricultural terraces. What did the Incas create that we use today?