Underground nuclear astrophysics was born twenty five years ago in the core of Gran Sasso, when LUNA (Laboratory for Underground Nuclear Astrophysics) started its activity with a 50kV accelerator,  implementing the visionary idea of Enrico Bellotti, Gianni Fiorentini and Claus Rolfs.

As a matter of fact, the extremely low laboratory background has allowed for the first time the realization of nuclear physics experiments with very small count rates, down to a couple of events per month. This way, the important reactions responsible for the hydrogen burning in the Sun could be studied down to the relevant stellar energies.

In addition to the solar phase of LUNA, a rich program lasting for several years and devoted to the study of the Big Bang nucleosynthesis and of the nucleosynthesis of the elements through the CNO, Mg-Al and Ne-Na cycles in different stars could be developed.

Today, after the first 25 years of LUNA, a new phase has started with the ambitious LUNA-MV project: a  3.5 MV accelerator is going to be installed in the Hall B of the underground laboratory.  This workshop aims  to introduce the new facility and its scientific program to the international community looking for possible fruitful collaborations.