  The purpose of this paper is to describe a relationship between maximally
supersymmetric domain walls and magnetic monopoles. We show that the moduli
space of domain walls in non-abelian gauge theories with N flavors is
isomorphic to a complex, middle dimensional, submanifold of the moduli space of
U(N) magnetic monopoles. This submanifold is defined by the fixed point set of
a circle action rotating the monopoles in the plane. To derive this result we
present a D-brane construction of domain walls, yielding a description of their
dynamics in terms of truncated Nahm equations. The physical explanation for the
relationship lies in the fact that domain walls, in the guise of kinks on a
vortex string, correspond to magnetic monopoles confined by the Meissner
effect.
