The international scientific colloquium “Spectroscopic Surveys with the ELT: A Gigantic Step into the Deep Universe” took place from 17 to 20 October 2017 at the Palacio de Congresos in Toledo (Spain).

The meeting was organized by the Complutense University of Madrid (UCM) with the support of the Instituto de AstrofĂ­sica de AndalucĂ­a (IAA-CSIC) and the Paris-Meudon Observatory (France). The meeting had an important participation of members of the scientific team of the MOSAIC instrument, the European Southern Observatory (ESO) and the Extremely Large Telescope (ELT) project itself, as well as many other interested researchers. The colloquium was supported by a generous grant from the Astronomy Infrastructure Network (RIA) and the Paris Observatory.