Over time, Roman architecture was modified as their urban requirements changed, and the civil engineering and building construction technology became developed and refined. The Roman concrete has remained a riddle, and <answer>even after more than 2,000 years some Roman structures still stand magnificently</answer>. The architectural style of the capital city was emulated by other urban centers under Roman control and influence. Roman cities were well planned, efficiently managed and neatly maintained.[citation needed]
Do any Roman structures still exist in our time?
even after more than 2,000 years some Roman structures still stand magnificently