1. Archaeological evidence:
- Indus seals have been found in Sumerian cities such as Ur and Kish.
- Sumerian artifacts, such as cylinder seals and beads, have been found at Harappan sites like Mohenjo-daro and Harappa.
2. Literary evidence:
- Sumerian texts mention trade with a region called "Meluhha," which is believed to be the Indus Valley.
- Harappan texts also refer to trade with a region called "Dilmun," which is believed to be Mesopotamia.
3. Similarities in artifacts and technologies:
- Both the Harappans and the Sumerians used similar technologies, such as wheeled carts and irrigation systems.
- They also produced similar artifacts, such as pottery, jewelry, and seals.
4. Geographical proximity:
- The Indus Valley and Sumer are both located in the Middle East, and they are relatively close to each other. This would have made it easier for trade to occur between the two regions.