  This paper investigates the evolution of a void and an adjacent galaxy
supercluster. For this purpose the quasispherical Szekeres model is employed.
The Szekeres model is an exact solution of the Einstein field equations. In
this way investigations of the evolution of the cosmic structures presented
here can be freed from such assumptions as small amplitude of the density
contrast. Studying the evolution of a void and an adjacent supercluster results
not only in better understanding the evolution of cosmic structures but also in
acquainting us with the Szekeres model.
  The main results include the conclusion that small voids surrounded by large
overdensities evolve slower than large, isolated voids do. On the other hand,
large voids enhance the evolution of adjacent superclusters which evolve much
faster than isolated galaxy superclusters.
