Some spacetimes containing non-rotating extremal isolated horizons

Well-known results demonstrate the uniqueness of extremal isolated horizons (equivalently near-horizon spacetimes) in (3+1)-dimensions. This paper briefly reviews some of these results and then explicitly constructs families of non-asymptotically flat, non-spherically symmetric spacetimes that nevertheless contain spherically symmetric extremal horizons that are isomorphic to those found in Reissner-Nordstrom spacetimes.