Small saphenous vein
The small saphenous vein is a continuation of the lateral marginal vein of the foot. It ascends posterior to the lateral malleolus, passing along the Achilles tendon and through the middle of the leg before piercing the deep fascia to enter the popliteal fossa. At this point, the small saphenous vein drains into the popliteal vein. Note that the small saphenous vein shares a common course with the sural nerve.