  We investigate the linear-chain configurations of four-$\alpha$ clusters in
$^{16}$O using a Skyrme cranked Hartree-Fock method and discuss the
relationship between the stability of such states and angular momentum. We show
the existence of a region of angular momentum (13-18 $\hbar$) where the linear
chain configuration is stabilized. For the first time we demonstrate that
stable exotic states with a large moment of inertia ($\hbar^2/2\Theta$ $\sim$
0.06-0.08 MeV) can exist.
