  We study magnetic order in the Heisenberg antiferromagnet on the checkerboard
lattice, a two-dimensional version of the pyrochlore network with strong
geometric frustration. By employing the semiclassical (1/S) expansion we find
that quantum fluctuations of spins induce a long-range order that breaks the
four-fold rotational symmetry of the lattice. The ordered phase is a
valence-bond crystal. We discuss similarities and differences with the extreme
quantum case S = 1/2 and find a useful phenomenology to describe the
bond-ordered phases.
