  We revisit the holographic description of the near horizon geometry of the
BTZ black hole in AdS$_3$ gravity, with a gravitational Chern-Simons term
included. After a dimensional reduction of the three dimensional theory, we use
the framework of nAdS$_2$/nCFT$_1$ to describe the near horizon physics. This
setup allows us to contrast the role of the gravitational and conformal anomaly
inherited from AdS$_3$/CFT$_2$ in the symmetry breaking mechanism of
nAdS$_2$/nCFT$_1$. Our results display how boundary conditions in the 3D
spacetime, combined with the gravitational anomaly, affect the holographic
description of the near horizon of the black hole relative to the physics near
the AdS$_3$ boundary.
