  We observed the nuclear region of NGC 4261 (3C270) with the VLBA at two
frequencies (1.6 and 8.4 GHz) simultaneously. We find that the position angle
of the parsec-scale radio axis agrees, within the errors, with the position
angle of the VLA-scale jet. Our observations also reveal basically symmetric
radio structures at both 1.6 and 8.4 GHz. Analysis of these images shows that
most of the central 10 pc of this source is not significantly affected by
free-free absorption, even though HST images show that the nucleus contains a
nearly edge-on disk of gas and dust on larger scales. Our highest angular
resolution image shows a very narrow gap in emission, which we interpret as an
absorption feature, just east of the radio core. This suggests that there may
be a small, dense inner accretion disk whose width is less than 0.1 pc. If the
inclination of this inner disk is close to that of the larger-scale HST disk it
becomes optically thin to 8.4 GHz radiation at a deprojected radius of about
0.8 pc. The brightness of the pc-scale jets falls off very rapidly on both
sides of the core, suggesting that the jets are rapidly expanding during the
the first several pc of their travel. It appears that there is a small dense
inner disk centered on the radio core (the base of the jets; less than 1 pc), a
low density bubble filling most of the the inner several pc of the nucleus
(within which the radio jets expand rapidly; ~10 pc), and a surrounding cool,
higher density region (of which the HST absorption disk is part; tens to
hundreds of pc) within which the transverse expansion of the radio jets, as
implied by the rate of decrease in jet brightness, is nearly halted.
