  We investigate the presence of domain walls in models described by three real
scalar fields. We search for stable defect structures which minimize the energy
of the static field configurations. We work out explict orbits in field space
and find several analytical solutions in all BPS sectors, some of them
presenting internal structure such as the appearence of defects inside defects.
We point out explicit applications in high energy physics, and in other
branches of nonlinear science.
