The first of thousands of people have traipsed through the country's newest and longest road tunnel.
On Sunday they were the first members of the public to get a close look at the $1.4 billion Waterview Connection, where twin 2.4km-long three-lane tunnels connect State Highways 20 and 16.
The 1.97km Lyttelton Tunnel was previously the longest.
It is hoped the tunnel will help improve traffic flows in the city blighted by congestion.
Prime Minister Bill English, using a pair golden scissors, cut the ceremonial ribbon with Transport Minister Simon Bridges and Finance Minister Steven Joyce.
The project was 60 years in the making and its opening was a big day for Auckland, Mr English said.
He was also able to take a car through the tunnel before members of the public walked it.
The tunnel has been billed as the biggest transport transformation in Auckland since the Harbour Bridge was opened in 1959.
It largely completes the Western Ring Route, a new 48km route linking the west of Auckland, Manukau, the city and the North Shore.
The project has been in construction for five years, using a gigantic boring machine dubbed Alice.
Further public open days will be held from Friday before the tunnel opens to traffic next month. Public interest has been strong with tickets being snapped up.