The new generation of wide Field of View (FoV) EAS instruments (HAWC and LHAASO) are both in the Northern hemisphere and have access to a limited portion of the Galactic plane. A crucial part of the sky needs to be studied as well. The Southern hemisphere includes the Galactic Center, the Inner Galaxy, and includes a large number of extremely interesting sources (neutron stars, black holes, SNRs, and extra-galactic AGNs) relevant to study fundamental physics and high-energy particle acceleration phenomena.
In this contribution we discuss the main drives for the design of a wide FoV gamma-ray telescope in the sub-TeV/TeV energy region.