The calcaneus, commonly known as the heel bone, is the largest bone in the foot. It is located at the back of the foot and forms the foundation of the rear part of the foot structure. The calcaneus plays a crucial role in walking, running, and jumping by providing support and stability. This bone connects with several other bones, including the talus above it and the cuboid in front. It also serves as an attachment point for important ligaments and tendons, such as the Achilles tendon, which connects the calf muscles to the heel.