Monument fort architecture building. A building with a dome on top of it

Indus civilization, also called Indus valley civilization or Harappan civilization, the earliest known urban culture of the Indian subcontinent. The nuclear dates of the civilization appear to be about 2500–1700 BCE, though the southern sites may have lasted later into the 2nd millennium BCE. Among the world’s three earliest civilizations—the other two are those of Mesopotamia and Egypt—the Indus civilization was the most extensive.