Abstract: I will describe the construction of entangled microstates of a pair of holographic CFTs whose dual semiclassical description includes big bang-big crunch AdS cosmologies in spaces without boundaries. The cosmology is supported by inhomogeneous heavy matter and it partially purifies the bulk entanglement of two auxiliary AdS spacetimes. In generic settings, the cosmology is an entanglement island contained in the entanglement wedge of one of the two CFTs. I will then describe the properties of the non-isometric bulk-to-boundary encoding map and an explicit, state-dependent boundary representation of operators acting on the cosmology. Finally, I will argue for a non-isometric to approximately-isometric transition of the bulk-to-boundary map for “simple” states on the cosmology as a function of the bulk entanglement, with tensor network toy models of the setup as a guide.