Notice on this image how the window lines on the building, as well as the roof, draw your eyes from left to right towards the center of the image where the two structures meet. The structure on the right plays a part in keeping your focus from going off of the page.
This may be the most simple and blatant example of leading lines. The car lights draw your eyes towards the back of the image, but the light on the rock at the back gives your eyes somewhere to rest.