The external iliac vein is a major blood vessel located in the pelvis. It is formed by the merging of the femoral vein and the great saphenous vein, which collect deoxygenated blood from the lower limbs. This vein plays a crucial role in returning blood to the heart, specifically draining into the common iliac vein. The external iliac vein runs alongside the external iliac artery and is situated deep within the pelvis. It is important for maintaining proper circulation in the legs and pelvis. Any issues with this vein can lead to complications such as deep vein thrombosis or other circulatory problems.