Image of supernova SN 1987A showing two annular light echoes. The image was taken with EFOSC in coronographic mode at the ESO 3.6-metre telescope, from La Silla Observatory, on February 1988, one year after the outburst. The colour coding shows the intensity contours in the image. Light echoes have been used as an efficient way of studying the structure of the interstellar medium close to the supernova. SN 1987A, detected in the nearby Large Magellanic Cloud, was the closest explosion of this kind for several centuries, the first visible by naked-eye for 383 years and definitely an event of the greatest relevance in modern astronomy. ESO telescopes have been observing this object for more than twenty years.