Complex network of nerves located in the upper abdomen
The celiac plexus, also known as the solar plexus because of its radiating nerve fibers, is a complex network of nerves located in the abdomen, near where the celiac trunk, superior mesenteric artery, and renal arteries branch from the abdominal aorta. It is behind the stomach and the omental bursa, and in front of the crura of the diaphragm, on the level of the first lumbar vertebra. The plexus is formed in part by the greater and lesser splanchnic nerves of both sides, and fibers from the anterior and posterior vagal trunks.
https://en.wikipedia.org/wiki/Celiac_plexus