  Open questions are still present in fundamental Physics and Cosmology, like
the nature of Dark Matter, the matter-antimatter asymmetry and the validity of
the particle interaction Standard Model. Addressing these questions requires a
new generation of massive particle detectors exploring the subatomic and
astrophysical worlds. ICARUS T600 is the first large mass (760 ton) example of
a novel detector generation able to combine the imaging capabilities of the old
famous "bubble chamber" with an excellent energy measurement in huge electronic
detectors. ICARUS T600 now operates at the Gran Sasso underground laboratory,
studying cosmic rays, neutrino oscillation and proton decay. Physical
potentialities of this novel telescope are presented through few examples of
neutrino interactions reconstructed with unprecedented details. Detector design
and early operation are also reported.
