  The topological structure of the black holes in 5-dimensional space-times
with a horizon diffeomorphic with the lens space has been discussed. It has
been shown that such a black hole can emerge from the crease set, which is
composed of the plumbings of several 2-spheres, of the event horizon. It has
also been shown that such configurations are realized in the Kastor-Traschen
solution of the Einstein-Maxwell system.
