Low-dimensional magnetism continues to be of great theoretical and experimental interest, as reduced dimensionality supports strong fluctuations that can result in novel states and excitations. One theme in this field is the understanding of magnetism in reduced dimensions using notions from topology. Examples include topological objects such as walls, vortices and skyrmions, which can potentially exist in the spin textures of a range of systems. In recent years, the experimental discovery of skyrmions in magnetic materials and of their self-organization into a skyrmion lattice, together with their potential for use as high density, low-energy sensors and magnetic storage, has made the investigation of such magnetic topological objects particularly important. I will discuss some recent investigations of skyrmion systems where we have used implanted muons as a probe of their magnetism. These demonstrate how muons can be used to investigate effects arising from disorder, the dynamics of centrosymmetric skyrmion-hosting materials and the depth dependence of the magnetism occurring in thin-film systems.