Recent observations show a large concentration of galaxies at high red
shift. At first sight, strong clustering of galaxies at high redshifts
seems to be in contradiction with the models of structure formation.
In this paper we show that such structures are a manifestation of the
strong clustering of rare peaks in the density field. We compute the f
requency of occurrence of such large concentrations of galaxies in som
e models of structure formation. (C) 1998 RAS.