Sydney Harbor Bridge Offers Climbs Beginning at 2:30 a.m.

BridgeClimb, one of Sydney's most successful tourism operators, can now take tours around the clock. But while the company has a licence to operate 24 hours a day, it will not - yet - be guiding scenic walks over the Harbour Bridge in the middle of the night.
Instead a dawn climb has been added to the schedule. The first group of climbers will now be required to report for pre-climb briefing at about 2.30am, to be on the top of the bridge's arch just as the sun starts to rise.
http://www.smh.com.au/articles/2002/12/17/1039656396108.html

Website:
http://www.bridgeclimb.com