  A magnetic helix arises in chiral magnets with a wavelength set by the
spin-orbit coupling. We show that the helimagnetic order is a nanoscale analog
to liquid crystals, exhibiting topological structures and domain walls that are
distinctly different from classical magnets. Using magnetic force microscopy
and micromagnetic simulations, we demonstrate that - similar to cholesteric
liquid crystals - three fundamental types of domain walls are realized in the
helimagnet FeGe. We reveal the micromagnetic wall structure and show that they
can carry a finite skyrmion charge, permitting coupling to spin currents and
contributions to a topological Hall effect. Our study establishes a new class
of magnetic nano-objects with non-trivial topology, opening the door to
innovative device concepts based on helimagnetic domain walls.
