Describe Gilgamesh's world in the novel, Gilgamesh: Man’s First Story.

To the north of his city of Uruk, one of the seven cities of ancient Sumer, lie the mountains of Mashu, to the west is the place in which the Sun sets to descend through the underground caverns and rise again in the Eastern Garden. Encircling this arrangement is a body of water called the Bitter River, the touch of which is fatal to the offender. To the north of the Bitter River are the mountains-without-end and, to the south, the sea-without-end.