Summary:The first stone of the future LSST telescope was laid on 14 April 2015 by the Chilean President Michelle Bachelet, at the Cerro Pachón site in the Chilean Andes. The LSST will be equipped with the most powerful digital camera ever built. The 8.4-meter-diameter telescope will shed light on the nature of dark energy, which accelerates the expansion of the Universe.< The LSST will achieve first light in 2019 and will be fully operational in 2022. The 8.4-meter-diameter telescope will image the sky systematically for ten years, providing a three-dimensional film of the entire visible Universe