  In this paper we present multifrequency VLA observations of the giant radio
galaxy 3C 449, obtained with high sensitivity and resolution in total intensity
and polarized flux. These images show the source morphology in great detail, in
particular we detect plumes and wiggles in the low brightness lobes. The source
is considerably polarized at all frequencies. The spectral index map between 5
GHz and 8.4 GHz shows that the northern region beyond 1' from the core has a
much flatter spectrum than the southern one. We analyse the jet dynamics, and
conclude that the jets are relativistic at the beginning, and decelerate
significantly within 10" (5 kpc) from the core. We compute the rotation
measure, and detect significant values within +-50 rad/m^2 of the expected
contribution of our Galaxy. The Faraday effect is likely to originate in an
external screen, which is most probably the intergalactic medium of the group
of galaxies around 3C pap449.
