  Certain peculiar features of Einstein-Hilbert (EH) action provide clues
towards a holographic approach to gravity which is independent of the detailed
microstructure of spacetime. These features of the EH action include: (a) the
existence of second derivatives of dynamical variables; (b) a non trivial
relation between the surface term and the bulk term; (c) the fact that surface
term is non analytic in the coupling constant, when gravity is treated as a
spin-2 perturbation around flat spacetime and (d) the form of the variation of
the surface term under infinitesimal coordinate transformations. The surface
term can be derived directly from very general considerations and using (d) one
can obtain Einstein's equations {\it just from the surface term of the action}.
Further one can relate the bulk term to the surface term and derive the full EH
action based on purely thermodynamic considerations. The features (a), (b) and
(c) above emerge in a natural fashion in this approach. It is shown that action
$A_{grav}$ splits into two terms $-S+\beta E$ in a natural manner \textit{in
any stationary spacetime with horizon}, where $E$ is essentially an integral
over ADM energy density and $S$ arises from the integral of the surface gravity
over the horizon. This analysis shows that the true degrees of freedom of
gravity reside in the surface term of the action, making gravity intrinsically
holographic. It also provides a close connection between gravity and gauge
theories, and highlights the subtle role of the singular coordinate
transformations.
