  We demonstrate the existence of chaotic geodesics for the Einstein-Rosen
standing gravitational waves. The complex dynamics of massive test particles
are governed by a chaotic heteroclinic network. We present the fractal
associated with the system under investigation. Gravitational standing waves
produce intricate patterns through test particles in a vague analogy to
mechanical vibrations generating Chladni figures and complicated shapes of
Faraday waves.
