The kidneys are two bean-shaped, reddish-brown organs located in the posterior abdomen, one on each side of the spine. They lie retroperitoneally (behind the peritoneum), typically extending from the vertebral levels T12 to L3. The right kidney is usually positioned slightly lower than the left due to the presence of the liver. Both kidneys sit just below the rib cage toward the middle of the back, with the upper parts partially protected by the 11th and 12th ribs. Each kidney has an adrenal gland sitting on top of it