  For studying the interplay of dipolar interaction and anisotropy energy in
systems of ultrafine magnetic particles we consider simple cubic systems of
magnetic dipoles with anisotropy axes pointing into the $z$-direction. Using
Monte Carlo simulations we study the magnetic relaxation from several initial
states. We show explicitely that, due to the combined influence of anisotropy
energy and dipole interaction, magnetic chains are formed along the
$z$-direction that organize themselves in frozen metastable domains of columnar
antiferromagnetic order. We show that the domains depend explicitely on the
history and relax only at extremely large time scales towards the ordered
state. We consider this as an indication for the appearence of frozen
metastable states also in real sytems, where the dipoles are located in a
liquid-like fashion and the anisotropy axes point into random directions.
