Climbing the Sydney Harbour Bridge is a great experience, and I should think a fairly unique one. There aren't many bridges that tourists are allowed to climb, and in any case this is not just any bridge. It is the longest single span suspension bridge in the world (1650 feet), the widest long bridge in the world (158 feet) and the world's largest steel arch bridge. (Boring note: some say the Bayonne Bridge in the US is 27 inches longer.)

It is also a very tall bridge, 440 feet above sea level at its highest. This height is very hard to appreciate until you do the climb, at which point it becomes very hard not to appreciate. Or  worry about.

Full details about climbing the bridge are here: www.bridgeclimb.com . According to the site, over a million people have climbed the Bridge since they started the operation in 1998. It is extremely well-organised, and I was mightly impressed by the care and thought that has gone into every stage of the process. Safety is, of course, a major concern, and the Bridge Climb people are very careful indeed that no-one comes to any harm, and that nobody and nothing ever falls off the Bridge.

You can't take any personal belongings with you on the climb, including cameras or camcorders. I understood the need to make sure nothing ever falls off the Bridge. However, I feel sure that if they wanted to, they could figure out a way to let people use their own cameras in a safe, can't-fall-off way.

They take a souvenir photograph of every group and every person who climbs, and you have the option to buy this photograph after the climb is over. Mine is below.

Understandably, the Bridge Climb people advertise their service with photos taken in glorious sunshine or at beautifully photogenic times of the day. When I climbed, the weather was atrocious to begin with, and just got worse from there. When you get to top of the Bridge, you don't need a weather forecast: you can actually see the weather that's on the way, coming in from miles away. When I climbed, this meant more dark clouds, more rain, more wind and a little thunder for good measure.

But I still loved every single second of this unique, unmissable and thrilling experience.