Edward Burger, the day after giving two lectures at Macquarie University, on the summit of the Sydney Harbour Bridge--134 meters above Sydney, Australia, August 3, 1999.

The Sydney Harbour Bridge is the largest steel arch bridge in the world. It's sweeping curve is 503 meters long, 134 meters high, and 49 meters wide.

The bridge weighs 52,800 tons and includes six million rivets. The bridge is substantially lighter when the large mass pictured in the center is removed.