Original: At its height the city covered over 30 km ² (over 11 1/2 square miles), and probably housed a population of over 150,000 people, possibly as many as 250,000.
Simplified: At its height the city covered over 30 km ² (over 11 1/2 square miles). It probably housed a population of over 150,000 people, possibly as many as 250,000.