Slow dynamics and metastability are often seen in models with quenched diso
rder, but rather harder to find in situations where no such disorder is pre
sent and energy or entropy barriers must be generated dynamically. Using Mo
nte Carlo simulations we show that the 3D four-spin interaction Ising model
, which possesses no quenched disorder, exhibits rather strong metastabilit
y in a broad range of temperatures around its first-order transition point,
due to the shape dependence of excitations in the model and the resulting
largeness of the associated critical droplets.