Abstract: Crystalline graphene in the rhombohedral stacking order provides an ideal platform to study electron correlation effects. It hosts gate-tunable flat electronic dispersion and Berry curvatures. The internal degrees of freedom, spin and valley, further enrich the possibilities of symmetry-broken ground states. In this talk, I will show a range of superconductivities observed in rhombohedral graphene, featuring spin polarization and valley polarizations. On the other hand, the same flat dispersion create a fertile playground for electron crystals. I will also show the signatures of Wigner and metallic Wigner crystals.