Which empire is known for its monumental architecture and engineering?

The Roman Empire is renowned for its monumental architecture and engineering, which set enduring standards for urban planning and construction techniques. Romans were pioneers in the use of concrete, enabling the construction of grand structures such as the Colosseum, aqueducts, and monumental basilicas. They excelled in engineering marvels, including the development of extensive road networks and innovative technologies like the arch and dome. This emphasis on large-scale architecture not only showcased their engineering prowess but also reflected the empire's power and cultural significance, influencing subsequent architectural styles across the world.

While each of the other empires also displayed impressive architecture, the scale and mastery of Roman engineering are particularly remarkable and influential in the history of architecture. The Ottoman Empire is celebrated for its beautiful mosques, the Byzantine Empire for its churches like Hagia Sophia, and the Persian Empire for its palatial complexes. However, the comprehensive range and systemic advancements in architecture and engineering during the Roman Empire make it the most notable in this regard.