There were the Mayans, Aztecs and Mississippi valley civilizations. They could arguably be called advanced with their architecture, city planning, astronomy... Tenochtitlan was as large as any city in the West and I think it would have still been a very large cityin the East. The area around lake titicaca also had pretty fancy irrigation
Also, cocoa, quinoa and the use of peppers, shows that some very healthy foods came from them also.
The post classical era in Europe was largely feudalistic and centered around the church, but Crop rotation and some other advances did occur and monestaries did keep up research in classical languages.