  The effect of smooth inhomogeneities near a superconductor boundary on the
magnetic penetration depth $\lambda$ is studied with emphasis on the
proximity-induced spatial dependence of the Cooper pair amplitude. The
influence of surface pair breaking or pair formation on $\lambda$ is described
within the Ginzburg-Landau theory, with no model assumptions, for both strongly
type-II and strongly type-I homogeneous superconductors. Generic values of
$\lambda$, which can differ greatly from the London penetration depth, are
identified and demonstrated to be induced by large-scale inhomogeneities, when
superconductivity is strongly suppressed on the surface.
