Sumerians believed in establishing special gates in cities:

Question

A. So that they might descend into the Netherworld.

B. For each of their individual nature gods.

C. As defense measures against more militant nations.

D. To honor first-time visitors.

Answer 1

The correct answer is A.

What few sources we have point to mythology. As the chapter "Entering Other Worlds: Gates, Rituals, and Cosmic Journeys in Sumerian Sources" states: "Several Sumerian myths dealing with journeys to the netherworld from the surface of the earth indicate that the entrance to the netherworld is marked by a gate or gatehouse." (Ragavan, 202) There is another quote: "In order to enter the netherworld, which is envisioned as a walled city, Inana must pass through a series of seven gates; at each gate she is required to give up an item of jewelry or clothing, in order to gain access." (Ragavan, 204)

These are cited from Heaven on Earth - Temples, Ritual, Cosmic Symbolism in the Ancient World, edited by Deena Ragavan.