  The problem in identifying the sites of origin of Galactic Cosmic Rays (CRs)
is reviewed. Recent observational evidence from very-high energy (VHE, energies
above 100 GeV) gamma-ray measurements is in contradiction with the surmise that
synchrotron radiation from relativistic electrons is indicative for hadron
acceleration. It rather points to a CR-acceleration efficiency of supernova
remnants (SNRs) below one percent, much less than the value required if these
objects were to be the main sources of Galactic cosmic rays (about 30%).
Observations of CR anisotropy and the emission of low-energy (energy < 10 GeV)
gamma-rays from the Galactic disk indicate that the sources of low-energy
cosmic rays are distributed with a Galactocentric radial scale length in the
order of 25 +- 10 kpc, much larger than expected if SNRs are the main sources
of CRs. These two facts - together with the body of evidence from CR isotope
abundances - strongly suggest that a new class of astrophysical objects -
distinct from SNRs and located manly in the outer reaches of our Galaxy - is
the major source of hadronic CRs in our Galaxy. The basic observational
features of ultra high-energy (UHE, energy > 10^{19} eV) CRs are most naturally
understood if the same CR sources accelerate CRs up to the highest observed CR
energies. Proposals for the nature of a new source class are mentioned. The
origin of CRs is still as much shrouded in mystery as it was in 1957, when
Philip Morrison wrote a seminal review about CR origin. The potential for
discoveries is thus great.
