Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Archaeological Ruins of Liangzhu City' has mentioned 'Hectares' in the following places:
Occurrence Sentence Text Source
Its interior area is 290 hectares, surrounded by clay walls which had six city gates.
At its center was a palace site that spanned 30 hectares and there was also evidence of an artificial flood protection design implemented within the city.
Outside of the walled area, remains are found for 700 hectares, the residences are said to be built in an urban planning system.