Complex spin structures feature a periodic variation of the local alignment of non-collinear magnetic moments. The number of systems showing non-trivial magnetic structuring steadily increases. Particularly, several uniaxial as well as two-dimensionally modulated magnetic states were found with unique rotational sense due to the spin-orbit based Dzyaloshinskii-Moriya-interaction. Another source for the modulated magnetic configurations is given by the frustration and competing higher-order exchange interactions arising due to the itinerant nature of electrons. One of the most exciting recent developments with respect to these non-trivial configurations is the emergence of magnetic quasiparticles, which are characterized by their enhanced temporal and thermal stability. In this review several aspects of the static and dynamic properties of the quasiparticles and other interfacial non-collinear magnetic structures will be addressed.