  We study the entanglement entropy in 1+1 dimensional conformal field theories
in the presence of interfaces from a holographic perspective. Compared with the
well-known case of boundary conformal field theories, interfaces allow for
several interesting new observables. Depending on how the interface is located
within the entangling region, the entanglement entropies differ and exhibit
surprising new patterns and universal relations. While our analysis is
performed within the framework of holography, we expect our results to hold
more generally.
