The Neretva River in Bosnia Herzegovina. Important as the boundary between first, the East and West Roman Empires--significant perhaps because these would come to represent Orthodox and Catholic faiths--and later on, the boundary between the Christian West and the Muslim East (under the Ottoman empire). Ground zero in a sense and a physical and metaphorical line between worlds that have clashed for centuries. It is so beautiful here it is hard to believe that such lines exist at all or that in today's world they may be intensifying.