  We present radio and optical observations of the peculiar radio galaxy
J1835+620, a member of a new sample of large angular size radio galaxies
selected from the NRAO VLA Sky Survey. Its optical counterpart is in a group of
at least three galaxies and shows strong, narrow emission lines which allow us
to measure its redshift as z=0.518. The derived cosmological distance places
J1835+620 among the giant radio galaxies. The outstanding aspect of J1835+620
at radio wavelengths is the existence of two symmetric bright components within
a typical Fanaroff-Riley type II structure. We interpret the source as the
result of two distinct phases of core activity. Radio maps and radio
polarization properties are consistent with a dense new ejection evolving
through an older underlying jet. We suggest that interaction with nearby
galaxies could be the reason for restarting the activity in J1835+620.
