The $200,000, 8.5-metre tall structure contains a time capsule that will provide Canberrans 100 years from now with insights into how the current generation lived, worked and played.

Both Ms Gallagher and territory historian David Headon linked the centenary column to the unbuilt ''commencement column'' envisaged by King O'Malley for the city a century ago.

The plinth for that column, which was to serve as Canberra's ''ceremonial heart'' and celebrate the empire, was the backdrop against which Lady Denman unveiled the name of the national capital on March 12, 1913.

''We have had federal governments that have waxed and waned about their love for Canberra but that is not true of the people of the city,'' Ms Gallagher said.

''We have finished off what should have happened 100 years ago.''

The Centenary Column is a community initiative, conceived and paid for by Canberra CBD Ltd. It has been built on the lower northern slopes of City Hill and is the work of artist Geoff Farquhar-Still.

A stainless steel obelisk rising from a granite-dressed concrete base, the column's surrounds are fenestrated with etched images celebrating the national capital's past 100 years.

Ms Gallagher said she was hopeful that the addition of the column and time capsule to the City Hill precinct would attract more visitors to the spot.

Safe access to City Hill is by the traffic lights on Northbourne Avenue and London Circuit. Sightseers can walk south along the Northbourne Avenue nature strip until they reach the monument at the gateway to the hill precinct.

The existing gravel path is to be replaced with a permanent concrete walkway in the near future.

While the costs for the improved access are being paid for by the ACT government, the time capsule and column have been funded by the commercial property owners of Civic, Braddon and Turner. Manny Notaras, the chairman of Canberra CBD Ltd, said the column meant far more to him than just a monument on City Hill.

''I would be one of the oldest Canberrans here today,'' he said. ''My late father came to Canberra just 14 years after the original foundation stone [for the unfinished commenced column] was laid.''

Centenary baby Julia Liso, aged nine months, represented the other end of the age spectrum.

She was also considered the person present most likely to be able to attend the opening of the time capsule in 100 years.

Proud parents Agnieszka and Andrew Liso said they would put it on her to-do list.

One bystander, who preferred to remain anonymous, said City Hill was an appropriate place to mark the birth of a great city.

''While I'm not aware of any Canberrans being born on City Hill, I'm pretty certain that - over the years - quite a few have been conceived here.''