  Recent experimental and theoretical ideas are laying the ground for a new era
in the knowledge of the parton structure of nuclei. We report on two promising
directions beyond inclusive deep inelastic scattering experiments, aimed at,
among other goals, unveiling the three dimensional structure of the bound
nucleon. The 3D structure in coordinate space can be accessed through deep
exclusive processes, whose non-perturbative content is parametrized in terms of
generalized parton distributions. In this way the distribution of partons in
the transverse plane will be obtained, providing a pictorial view of the
realization of the European Muon Collaboration effect. In particular, we show
how, through the generalized parton distribution framework, non nucleonic
degrees of freedom in nuclei can be unveiled. Analogously, the momentum space
3D structure can be accessed by studying transverse momentum dependent parton
distributions in semi-inclusive deep inelastic scattering processes. The status
of measurements is also summarized, in particular novel coincidence
measurements at high luminosity facilities, such as Jefferson Laboratory.
Finally the prospects for the next years at future facilities, such as the
12~GeV Jefferson Laboratory and the Electron Ion Collider, are presented.
