  We study dynamical aspects of three--dimensional gonihedric spins by using
Monte--Carlo methods. The interest of this family of models (parametrized by
one self-avoidance parameter $\kappa$) lies in their capability to show
remarkably slow dynamics and seemingly glassy behaviour below a certain
temperature $T_g$ without the need of introducing disorder of any kind. We
consider first a hamiltonian that takes into account only a four--spin term
($\kappa=0$), where a first order phase transition is well established. By
studying the relaxation properties at low temperatures we confirm that the
model exhibits two distinct regimes. For $T_g< T < T_c$, with long lived
metastability and a supercooled phase, the approach to equilibrium is well
described by a stretched exponential. For $T<T_g$ the dynamics appears to be
logarithmic. We provide an accurate determination of $T_g$. We also determine
the evolution of particularly long lived configurations. Next, we consider the
case $\kappa=1$, where the plaquette term is absent and the gonihedric action
consists in a ferromagnetic Ising with fine-tuned next-to-nearest neighbour
interactions. This model exhibits a second order phase transition. The
consideration of the relaxation time for configurations in the cold phase
reveals the presence of slow dynamics and glassy behaviour for any $T< T_c$.
Type II aging features are exhibited by this model.
