What are the four ancient civilizations of the Old World?

 The four ancient civilizations of the Old World are typically considered to be:

Mesopotamia (Sumer): Located in the region between the Tigris and Euphrates rivers, Mesopotamia is often regarded as one of the earliest cradles of civilization. Sumer was one of the earliest known civilizations within Mesopotamia, known for its city-states, invention of writing (cuneiform), monumental architecture (such as ziggurats), and advancements in mathematics, astronomy, and governance.

Ancient Egypt: Centered along the Nile River in Northeast Africa, Ancient Egypt is renowned for its monumental architecture (such as pyramids and temples), sophisticated writing system (hieroglyphs), religious beliefs (including the worship of numerous gods and goddesses), and contributions to art, science, and medicine.

Indus Valley Civilization: Flourishing in the region of modern-day Pakistan and northwest India, the Indus Valley Civilization (also known as the Harappan Civilization) was one of the world's earliest urban societies. Known for its well-planned cities, advanced drainage systems, and trade networks, the Indus Valley Civilization thrived around the Indus River and its tributaries.

Ancient China: Ancient China developed along the Yellow River (Huang He) and the Yangtze River in East Asia. It is known for its early dynasties, such as the Xia, Shang, and Zhou, as well as for its significant contributions to philosophy (Confucianism, Taoism), governance (including the invention of paper, silk production, and the Great Wall), and culture (such as calligraphy, poetry, and traditional medicine).

These four civilizations are often highlighted due to their significant contributions to human history, including the development of complex societies, advancements in various fields, and enduring legacies that continue to influence the world today.