What structure was built between 1-1000 ad?

Between 1-1000 AD, many significant structures were built, including the Roman Colosseum, completed in 80 AD, which served as a grand arena for public spectacles. Additionally, the Great Wall of China saw extensive construction during this period, particularly under the Ming Dynasty, while monumental religious structures like the Hagia Sophia in Istanbul were started in 537 AD. These structures reflect the architectural and engineering advancements of their respective cultures.