The largest and longest vein in the human body goes from the foot up the leg to the hip. It is called the Great Saphenous Vein or the Long Saphenous Vein. The purpose of this great vein is the delivery of blood from the ankle, lower leg and the thigh to the vein in the femur bone. The Great Saphenous Vein has a large blood vessel running near the inside surface of the leg from the ankle to the groin. There are around 10-20 valves in this vein. It is used in several medical procedures due to its size and superficial location.