While there are various theories regarding the decline—such as Aryan invasion, tectonic shifts, or ecological changes—no single factor is definitely known. Excavations suggest a gradual decline between 1800 BC and 1700 BC rather than a sudden end.

Archaeologists have identified seven distinct layers of inhabitation at Mohenjo-daro. These layers indicate that the city was destroyed and rebuilt multiple times, likely due to recurring flooding from the Indus River.

The Harappan culture is renowned for its immaculate town planning, which distinguishes it from other ancient civilizations. The cities were designed with a grid system, organized drainage, granaries, and structured residential areas, reflecting the work of brilliant architectural engineering.

Terracotta figurines excavated from Harappan sites frequently depict oxen, buffaloes, pigs, goats, sheep, and humped bulls. However, the cow is notably absent from this art form. The cow became a central figure of importance later during the Vedic culture.

The drainage system of Mohenjo-daro is considered the most elaborate and advanced of antiquity. It featured covered brick drains, soak pits, and manholes, reflecting a municipal focus on hygiene that was unmatched by any other contemporary civilization.

The Harappans had a diverse agricultural portfolio. They grew wheat and barley as staples, along with peas, lentils, linseed, and mustard. They are also credited with being the first to cultivate cotton. While rice remains were found, it was not a primary crop compared to wheat and barley.

Harappa is located in the Punjab Province of Pakistan on the old bed of the River Ravi. Conversely, Kalibangan (Rajasthan), Alamgirpur (Uttar Pradesh), and Lothal (Gujarat) are all located within modern-day India.

Sutkagan Dor is the westernmost known archaeological site of the Indus Valley Civilization. It is located in the Baluchistan province of Pakistan, near the Iranian border, whereas Rangpur, Surkotada, and Desalpur are located in Gujarat, India.

While the Harappans had excellent town planning, their underground drainage system was unique in the ancient world. Almost every house was connected to street drains, which were covered, paved with bricks, and equipped with manholes for cleaning, showing an unparalleled focus on sanitation.

Unlike Mesopotamia or Egypt, the Indus Valley Civilization lacks evidence of monumental temples, palaces, or clear public places of worship. Religion appears to have been a more private matter, or rituals were performed in places like the Great Bath rather than temple structures.