Abstract: I will describe the construction of infinitely many complete non-compact 8-dimensional Ricci-flat manifolds with holonomy Spin(7). Prior to this work there was only a handful of known examples of such manifolds. The construction relies on the study of the adiabatic limit of metrics with exceptional holonomy on principal Seifert circle bundles over asymptotically conical orbifolds. The metrics we produce have an asymptotic geometry (so-called ALC geometry) that generalises to higher dimensions the geometry of 4-dimensional ALF hyperkähler metrics. We apply our construction to asymptotically conical metrics arising from self-dual Einstein 4-orbifolds with positive scalar curvature and produce complete non-compact Spin(7)-manifolds with arbitrarily large second Betti number and infinitely many distinct families of ALC Spin(7)-metrics on the same smooth 8-manifold.