How did ancient people imagine the shape of the Earth?

In ancient times, people imagined the earth to be flat, disk-shaped. This idea of the earth finds its origin in: the beliefs of the ancient Egyptians, Babylonians, Buddhism, Hinduism, etc. In Buddhism and Hinduism, the land is considered as a giant disc in the center of which is the huge Mount Meru, and its slopes are the continents. The stars, the moon and the sun revolve around this mountain. Also, the ancient people imagined a flat land, which is supported by three elephants and a large turtle.