  The static, plane symmetric solutions and cylindrically symmetric solutions
of Einstein-Maxwell equations with a negative cosmological constant are
investigated. These black configurations are asymptotically anti-de Sitter not
only in the transverse directions, but also in the membrane or string
directions. Their causal structure is similar to that of Reissner-Nordstr\"{o}m
black holes, but their Hawking temperature goes with $M^{1/3}$, where $M$ is
the ADM mass density. We also discuss the static plane solutions in
Einstein-Maxwell-dilaton gravity with a Liouville-type dilaton potential. The
presence of the dilaton field changes drastically the structure of solutions.
They are asymptotically ``anti-de Sitter'' or ``de Sitter'' depending on the
parameters in the theory.
