Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Archaeological Monuments Zone of Xochicalco' has mentioned 'Infrastructure' in the following places:

Occurrence Sentence	Text Source
In this period of political instability and commercial competition, the military infrastructure became crucial, and new settlements were founded at easily defensible sites, equipped with ramparts, moats, palisades, bastions, and citadels.	UNESCO