  We compute the gravitational entropy of 'spherical Rindler space', a
time-dependent, spherically symmetric generalization of ordinary Rindler space,
defined with reference to a family of observers traveling along non-parallel,
accelerated trajectories. All these observers are causally disconnected from a
spherical region H (a 'hole') located at the origin of Minkowski space. The
entropy evaluates to S = A/4G, where A is the area of the spherical
acceleration horizon, which coincides with the boundary of H. We propose that S
is the entropy of entanglement between quantum gravitational degrees of freedom
supporting the interior and the exterior of the sphere H.
