The summit of Canberra's Mount Ainslie would undergo a significant reorientation and return to nature as part of the winning entry in an open design competition.
A circular lookout could be built within five years, with new parking, entry signage, picnic areas, lawns and plantings also included by designers Sue Barnsley and Jane Irwin. The pair won the competition, first announced in December by the ACT government and National Capital Authority.
No funding or timeline has been attached to the plan. Preliminary sketches will be prepared by the middle of the year but the cost would have to be included in future ACT or federal government budgets. The Turnbull government said the plan was a vision for the next decade.
The plan includes stages over two, five and 10 years, including new trail connections, amenities and a share way road to accommodate cars, bikes and pedestrians. It would see proper consideration given to the Mount Ainslie end of the Walter Burley Griffin land axis and restore surrounding bushland.
The summit would better engage with the natural ridgeline, better frame views over Canberra and reduce concrete and paving.
Ms Irwin said the plans would bring a more dramatic sense of the view from the summit.
"It will be tighter and higher, poking further out into the view. You will get a much more physical experience," she said.
"It is really about Griffin's idea of how the city is connected to nature. This is the spot where you see that connect but when you are on the summit now, you really don't experience it."
"You will get a much closer experience of the bush."
Ms Barnsley said the extended lookout would restore views envisaged in the original Griffin plan for Canberra.
"At the moment the view is kind of distorted and you don't know exactly where the two summits intersect along Griffin's land axis. The lookout would mark that spot in a really strong way.
"The visitor experience will be heightened. It is a matter of improving the facilities... focusing the view and making a series of gathering spots threaded around the whole of the summit and allowing more picnicking on the west side, making grass and meadows around the car park."
The plans could be completed at one time if the two governments provide enough money, Ms Barnsley said. Otherwise it could be built in instalments.
Minister for Transport and Municipal Services Meegan Fitzharris said three entrants were shortlisted and assessed by a panel of jurors from the Australian Institute of Landscape Architects, the National Capital Authority and Territory and Municipal Services Directorate.
The two other finalists were Canberra firm Redbox Design Group and Western Australia's Blackwell and Associates.
The designs by the three finalists will go on display at the Civic Library until March 3.