Compared to free space, the interaction between light and matter can become considerably more involved when atoms or other emitters are coupled to structured electromagnetic environments such as 1D waveguides or 2D photonic lattices. Under such conditions the strong confinement and restricted propagation direction can give rise to effective infinite-range interactions between the emitters, correlated decay processes or the formation of atom-photon bound states. In 2D systems, additional engineering tricks can be used to create synthetic magnetic fields for light, which gives rise to even more exotic forms of chiral light-matter interaction effects.