  We present sub-arcsecond resolution ground-based near-infrared images of the
central regions of a sample of twelve barred galaxies with circumnuclear star
formation activity, which is organized in ring-like regions typically one
kiloparsec in diameter. We also present Hubble Space Telescope near-infrared
images of ten of our sample galaxies, and compare them with our ground-based
data. Although our sample galaxies were selected for the presence of
circumnuclear star formation activity, our broad-band near-infrared images are
heterogeneous, showing a substantial amount of small-scale structure in some
galaxies, and practically none in others. We argue that, where it exists, this
structure is caused by young stars, which also cause the characteristic bumps
or changes in slope in the radial profiles of ellipticity, major axis position
angle, surface brightness and colour at the radius of the circumnuclear ring in
most of our sample galaxies. In 7 out of 10 HST images, star formation in the
nuclear ring is clearly visible as a large number of small emitting regions,
organised into spiral arm fragments, which are accompanied by dust lanes. NIR
colour index maps show much more clearly the location of dust lanes and, in
certain cases, regions of star formation than single broad-band images.
Circumnuclear spiral structure thus outlined appears to be common in barred
spiral galaxies with circumnuclear star formation.
