This symbol is similar to that for the noun caravanserai. However, it does not have the built (straight) roads, and the structures within the area have softer edges which suggests tents. Hence, this is the noun encampment.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-309 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 77: Collections in India: Suomalainen Tiedeakatemia.
Image Credit:
Indus Script Sign Number 2522: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.