  Topological photonic systems, with their ability to host states protected
against disorder and perturbation, allow us to do with photons what topological
insulators do with electrons. Topological photonics can refer to electronic
systems coupled with light or purely photonic setups. By shrinking these
systems to the nanoscale, we can harness the enhanced sensitivity observed in
nanoscale structures and combine this with the protection of the topological
photonic states, allowing us to design photonic local density of states and to
push towards one of the ultimate goals of modern science: the precise control
of photons at the nanoscale. This is paramount for both nano-technological
applications and also for fundamental research in light matter problems. For
purely photonic systems, we work with bosonic rather than fermionic states, so
the implementation of topology in these systems requires new paradigms. Trying
to face these challenges has helped in the creation of the exciting new field
of topological nanophotonics, with far-reaching applications. In this
prospective article we review milestones in topological photonics and discuss
how they can be built upon at the nanoscale.
