The tailbone can be felt. The human spine is composed of the cervical, thoracic, lumbar, sacral and caudal vertebrae, and the tailbone is the very end of the spine, located below the sacrum, which together with the sacrum forms the sacral joint. The tailbone consists of 3-5 bony pieces, with the anus in front of the tailbone and the skin behind it. The tailbone is a tiny triangle, a slightly curved bony structure, located roughly at the midline of the buttocks. In adults, there is no longer a spinal cord after the second lumbar vertebra, leaving the cauda equina nerve running through it. If you touch down along the middle of the buttocks on both sides, the bone you feel is the caudal vertebra, which is generally easier to touch in front of the anus when squatting. If you sit for a long time, the tailbone is more likely to be squeezed and rubbed with a hard chair.