public class MoveTowards : MonoBehaviour {

    int currentStartPoint;
    private Vector3 startMarker, endMarker;
    public float speed = 1.0F;
    private float startTime;
    private float journeyLength;
    public float smooth = 5.0F;
    List<Vector3> tempPositionList = new List<Vector3>();
    List<Vector3> positionList = new List<Vector3>
        {
            new Vector3(4,0,0),
            new Vector3(4,0,2),
            new Vector3(4,0,4),
            new Vector3(2,0,4),
            new Vector3(0,0,4),
            new Vector3(-2,0,4),
            new Vector3(-4,0,4),
            new Vector3(-4,0,2),
            new Vector3(-4,0,0),
            new Vector3(-4,0,-2),
            new Vector3(-4,0,-4),
            new Vector3(-2,-0,-4),
            new Vector3(0,0,-4),
            new Vector3(2,0,-4),
            new Vector3(4,0,-4),
            new Vector3(4,0,-2),
            new Vector3(2,0,-2),
            new Vector3(0,0,-2),
            new Vector3(-2,0,-2),
            new Vector3(-2,0,0),
            new Vector3(-2,0,2),
            new Vector3(0,0,2),
            new Vector3(2,0,2),
            new Vector3(2,0,0),
            new Vector3(0,0,0)
        };
    void Start()
    {
        currentStartPoint = 0;
        SetPoints();
    }
    public void SetPoints()
    {
        startMarker = positionList[currentStartPoint];
        endMarker = positionList[currentStartPoint + 1];
        startTime = Time.time;
        journeyLength = 2;
    }

    void Update()
    {
        Debug.Log(positionList.Count);
        float distCovered = (Time.time - startTime) * speed;
        float fracJourney = distCovered / journeyLength;
        transform.position = Vector3.Lerp(positionList[currentStartPoint], positionList[currentStartPoint + 1], fracJourney);
        if (fracJourney >= 1f && currentStartPoint + 1 < positionList.Count)
        {
            currentStartPoint++;
            SetPoints();
        }
    }

}