The present invention relates to a wall block for use in a segmental retaining wall system. The wall block comprises an interior face for forming an interior surface of a segmental retaining wall, an exterior face for forming an exterior surface of the segmental retaining wall, first and second sides...http://www.google.com.au/patents/US6318934?utm_source=gb-gplus-sharePatent US6318934 - Segmental retaining wall system
