Protesters reminded those at the War Memorial Park opening that war was not something to be taken lightly.

Pukeahu National War Memorial Park in Wellington was officially opened on Saturday morning.

John Key was in attendance with his wife Bronagh at the Pukeahu War Memorial Park opening.

About 500 people attended the opening in Wellington.

Pukeahu National War Memorial Park in Wellington was officially opened on Saturday morning.

Despite a strong southerly, more than 500 people attended the official opening of the Pukeahu National War Memorial Park in Wellington.

Saturday's opening was timed as part of the focus on the 100th commemorations of the First World War.

Governor General Sir Jerry Mateparae addressed the crowd under grey skies, saying it was an honour to stand there as a former soldier.

"This is an historic occasion as we re-dedicate this sacred site," he said.

"Pukeahu is our national memorial to all those brave New Zealanders and at its ceremonial centre is He Toa Matangaro No Aotearoa - New Zealand's Unknown Warrior.

"In time it will take its place as a destination for people who want to learn about our past. Long after we are gone Pukeahu will be here."

Prime Minister John Key attended the event with his wife, Bronagh.

"In 1919 the Government agreed to build a National War Memorial here in Wellington," he said.

"It was to be placed so it would be visible from any part of the city, from ships entering the harbour, and from Parliament so that future governments would never forget the sacrifice that had been made.

"Today, with the opening of Pukeahu National War Memorial Park we add another dimension and a place for New Zealanders to come together on ceremonial occasions.

"We have created a place imbued with deep significance, which will be meaningful to New Zealanders for many generations to come."

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Wellington musician Louis Baker performed his song Love with the Air Force Band.

Beforehand, he said he would be thinking of his grandfather Frederick Baker, who was a commanding officer of the 28th Maori Battalion in 1942.

The War Museum also formally opened its doors to Sir Peter Jackson's Great War Exhibition.

The exhibition tells the story of World War 1 from its pre-1914 origins to the Treaty of Versailles in 1919, honouring the role many Kiwis played.

The two-and-a-half-year construction project was located in front of the former national museum on Buckle Street, Wellington, a site significant in Maori history known as "sacred hill".

It was unofficially opened with a pre-dawn blessing on March 25.

The site could expect another good turnout on Anzac Day, for a dawn service.

BY THE NUMBERS

775,000 work hours

35,000 square metres of soil removed

21,000 square metres of park

17,000 perennial plants

6500 square meters of pathway

4500 square metres of granite paving

3850 square metres of grass

3000 square metres of garden

2700 truck and trailer loads of soil carted away

1820 tonnes of concrete

1800 workers spent time on site

1000 square-metre ceremonial plaza in front of the war memorial

300 metre-long Arras Tunnel underneath

220 workers on site at the peak of construction

165 trees of six different types

120 million to build the park and tunnel underneath

75 olive trees

46 bollards to restrict car movements

35 seats made of Eucalyptus Saligna timber

30 months to build the tunnel and park

32 pohutakawa trees

25 kowhai trees

18 eucalyptus trees

10 titoki trees

5 northern rata trees

1 Tomb of the Unknown Warrior

DID YOU KNOW?

The creation of Pukeahu National War Memorial Park commemorates the 100th anniversary of the Gallipoli campaign, the first major battle for Anzac soldiers in World War I.

More than 300,000 Kiwis have served their country in military conflict. About 30,000 have died serving their country and almost 8000 have no known grave. The Tomb of the Unknown Warrior, on the forecourt outside the National War Memorial, was built to remember them.

The 21,000 square metre Pukeahu National War Memorial Park precinct is roughly the size of three rugby fields.

The park was named Pukeahu because the Maori who once lived in the area called the hill Pukeahu and had a pa site there. They grew vegetables on the hillside terraces leading up to where the carillon now stands.

Discussions about having a national place of remembrance on the elevated site where the park now stands began shortly after World War I. The National War Memorial and Carillon appeared in 1932, the Hall of Memories followed in 1964, and the Tomb of the Unknown Warrior was placed there in 2004.

The park contains a memorial commissioned by the Australian Government to pay tribute to the Anzac military relationship. It features 15 columns of red sandstone, representing Australia, interwoven with bands of grey basalt, to represent New Zealand. A British memorial is expected to follow.