London has the Thames Path, Italy the Cinque Terre, Spain the caminos of various saints but Sydney Harbour has the world's most stunning walk.

Few realise it is even there.

Laced along 70 kilometres of Sydney shoreline are heritage sites, spectacular scenery, bush hideaways and beaches that have seen the Eora Nation, the arrival of the First Fleet, the building of the Harbour Bridge and Opera House.

There are paths, trails and tracks by the harbour but nobody has ever thought about connecting them in one great walk.

Now two inveterate late night walkers have come up with the Bondi to Manly Walk during their peregrinations.

John Faulkner a former Minister for Defence during Kevin Rudd's first prime ministerial stint, and Lachlan Harris, Rudd's then press secretary, hit on Bondi/Manly as they walked the walk and talked the talk around Canberra's Lake Burley Griffin.

"It was a matter of joining the dots," said Mr Faulkner, who retired from the Senate in 2015.

It could be achieved with a modest public works program and by providing maps and signage at key points for walkers.

Both men stressed the walk was an apolitical proposal with diverse support.

"It's a very simple beautiful idea to get the maximum benefit out of existing public land," said Mr Harris who now runs the consumer network One Big Switch.

"So many ideas in recent years have been motorways, and casinos and billion-dollar projects. This is the opposite – it's the simple utilisation of good public land."

A connected walk from Bondi to Manly could be a shining gem for Sydney, said Tim Williams, chief executive of the Committee for Sydney.

"Walkable cities are successful cities. This idea is not just a nice to have. It's a must for the city," said Mr Williams.

Di Westaway, CEO of Wild Women on Top, had to deal with up to 20 authorities when organising the annual Sydney Coastrek: "Captain Arthur Phillip called it 'the finest harbour in the world ...', is it not simply common sense to show it off as the Great Sydney Walk?"