- Cholistan is located in Pakistan, south of Punjab and east of Sindh. - It was a core area of the Mature Harappan civilization. - The decline of the Harappan civilization varied regionally, but the period from around 1900 BCE onwards is generally considered the Late Harappan phase or Post-Urban Harappan. - Factors like climatic change, changes in river courses (e.g., the Ghaggar-Hakra river), and potentially other socio-political factors contributed to the decline and abandonment of sites.