Photoelectron emission microscopy (PEEM) has proven to be a versatile analytical technique in surface science. When operated with circularly polarized light in the soft x-ray regime, however, photoemission microscopy offers a unique combination of magnetic and chemical information. Exploiting the high brilliance and circular polarization available at a helical undulator beamline, the lateral resolution in the imaging of magnetic domain structures may be pushed well into the sub-micrometer range. Using a newly designed photoemission microscope we show that under these circumstances not only domains, but also domain walls can be selectively investigated. The high sensitivity of the technique yields a sizable magnetic contrast even from magnetic films as thin as a fraction of a single monolayer. The combination of chemical selectivity and information depth is successfully employed to investigate the magnetic behavior of buried layers and covered surfaces. This approach offers a convenient access to magnetic coupling phenomena in magnetic sandwiches.