  The Pierre Auger Observatory has been detecting ultra-high energy cosmic rays
(UHECRs) for more than fifteen years. An essential feature of the Observatory
is its hybrid design: cosmic rays above $100~$PeV are detected through the
observation of the associated air showers with different and complementary
techniques, from surface detector arrays and fluorescence telescopes to radio
antennas. The analyses of the multi-detector data have enabled high-statistics
and high-precision studies of the energy spectrum, mass composition and
distribution of arrival directions of UHECRs. The resulting picture is
summarized in this contribution. While no discrete source of UHECRs has been
identified so far, the extragalactic origin of the particles has been recently
determined from the arrival directions above 8~EeV, and the ring is closing
around nearby astrophysical sites at higher energies. Also, the established
upper limits on fluxes of UHE neutrinos and photons have implications on dark
matter and cosmological aspects that are also presented in this contribution.
