  We discuss the basic difficulties in understanding the origin of the highest
energy particles in the Universe - the ultrahigh energy cosmic rays (UHECR). It
is difficult to imagine the sources they are accelerated in. Because of the
strong attenuation of UHECR on their propagation from the sources to us these
sources should be at cosmologically short distance from us but are currently
not identified. We also give information of the most recent experimental
results including the ones reported at this conference and compare them to
models of the UHECR origin.
