Celiac plexus is located:
Celiac plexus is present on the anterior side of the aorta around the beginning of celiac trunk .

It lies over the anterolateral surface of the aorta at the T12 / L1 vertebral level.
Celiac plexus is retroperitoneal and located behind the stomach and the omental bursa, and in front of the crura of the diaphragm.
In pictorial representation it appear anteromedial to sympathetic trunks as well, though no such statement is mentioned in standard textbooks.
Frequently celiac plexus block (fluoroscopically guided injection) is performed by pain management specialists and radiologists is performed via CT guidance.
Intractable pain related to chronic pancreatitis is an important indication for celiac plexus ablation.

KEY CONCEPT:
Celiac plexus is the largest visceral plexus and is located deep in the retroperitoneum, over the anterolateral surface of the aorta and around the origin of the celiac trunk.
Anterolateral to aorta
Poterolateral to aorta
Anteromedial to lumbar sympathetic chain
Poterolateral to lumbar sympathetic chain