Which is the smallest organ in the body?

The pineal gland is the smallest organ in the human body. It is located near the center of the brain, in a groove between the hemispheres. The pineal gland is shaped like a tiny pine cone, hence its name, and is about the size of a grain of rice. It plays a crucial role in regulating the body's internal clock by producing melatonin, a hormone that helps control sleep-wake cycles.