  It is nowadays clear that General Relativity cannot be the definitive theory
of Gravitation due to several shortcomings that come out both from theoretical
and experimental viewpoints. At large scales (astrophysical and cosmological)
the attempts to match it with the latest observational data lead to invoke Dark
Energy and Dark Matter as the bulk components of the cosmic fluid. Since no
final evidence, at fundamental level, exists for such ingredients, it is clear
that General Relativity presents shortcomings at infrared scales. On the other
hand, the attempts to formulate more general theories than Einstein's one give
rise to mathematical difficulties that need workarounds that, in turn, generate
problems from the interpretative viewpoint. We present here a completely new
approach to the mathematical objects in terms of which a theory of Gravitation
may be written in a first-order (a' la Palatini) formalism, and introduce the
concept of Dark Metric which could completely bypass the introduction of
disturbing concepts as Dark Energy and Dark Matter.
