Clearly - famous Harbor Bridge in Sydney. When we were getting back from our trip on The Central Coast, I & Arty, we heard on the radio in that morning, that the Bridge is supposed to be undermined by terrorists. We got pretty anxious, because the Bridge connects north Sydney, where we were coming from Freeway & south Sydney, where we lived. Luckily, antiterrorist forces supervised the Bridge carefully for many days - nothing happened.