<P> The Metropolitan Museum of Art - Human Headed Winged Lion and Bull from Nimrud, companion pieces to those in the British Museum </P> <Li> <P> Detail, University of Chicago Oriental Institute . Gypsum (?), Dur - Sharrukin, entrance to the throne room, c. 721 - 705 B.C </P> </Li> <P> Detail, University of Chicago Oriental Institute . Gypsum (?), Dur - Sharrukin, entrance to the throne room, c. 721 - 705 B.C </P> <Li> <P> Cuneiform script on the back of a lamassu in the University of Chicago Oriental Institute . </P> </Li>

What purpose did the lamassu guardian gates serve