'Risk ' is not a word I particularly want to encounter when I'm about to be taken to' />

Attempt Skywalk at your own risk," the sheet warns ominously.

"Risk" is not a word I particularly want to encounter when I'm about to be taken to the top of Sydney's highest tower to step on to its new, precariously-perched, outdoor glass-bottomed viewing platforms, 250m above the ground.

But I sign up, and step into my jumpsuit.

"Now guys," says one of the guides, as if reading my thoughts. "They're called skysuits, okay, not jumpsuits - there'll be no jumping today."

Touche.

We take the lifts to Sydney Tower's regular (indoor) observation deck, and then we're led through a narrow tunnel towards the Skywalk. Our harnesses are tethered to a titanium railing before we step outside.

The spectacular views quickly quash any fear I'm feeling: Hyde Park, St Mary's, King's Cross, Bondi, the ocean, all laid out before me.

In the distance, just beyond North Head, the Spirit of Tasmania is pulling in to Sydney Harbour. Though it's only 10m higher than the regular observation deck, the scope and quality of the view, out from behind those glass walls, is immeasurably superior.

We're led all around the tower's golden turret as our guide, via a walkie-talkie link-up, points out features and tells amusing stories about what we can see.

To the north, the Harbour Bridge, Opera House and Manly Beach are all visible; to the west Darling Harbour, the Anzac Bridge, all the way to the Blue Mountains in the distance; and to the south, the Sydney Cricket Ground, airport and Botany Bay.

Short of a city chopper ride, there's no other place to get a view of Sydney this good.

We do another loop of the turret, this time taking in the glass-bottomed platforms.

My first step over the edge is a tentative one, but I quickly relax. Staring straight down at Sydney's streets, as the people below criss-cross like ants, is quite a strange and unnerving experience, one you won't forget.

Though it's being pitched as an attraction for daredevils, the Skywalk is suitable for everyone but those with a chronic, unbeatable fear of heights.

This is not an extreme activity like bungy-jumping or skydiving; in fact, thrillseekers under the illusion they're in for a hell of a ride may be somewhat disappointed.

But at twice the height of Bridgeclimb - and minus the unforgiving climb - for everyone else Skywalk is well worth a go.

Sydney Skywalks

Skywalk tours operate from 9am to 10pm daily, with the last trip departing at 8.15pm. daytime walks are available from $135 for adults. dusk and dawn walks are also available.

www.skywalk.com.au

- AAP