  We construct uncountably many isoparametric families of hypersurfaces in
Damek-Ricci spaces. We characterize those of them that have constant principal
curvatures by means of the new concept of generalized Kahler angle. It follows
that, in general, these examples are inhomogeneous and have nonconstant
principal curvatures. We also find new cohomogeneity one actions on
quaternionic hyperbolic spaces, and an isoparametric family of inhomogeneous
hypersurfaces with constant principal curvatures in the Cayley hyperbolic
plane.
