Te Papa has revealed the country's most-visited exhibition 'Gallipolli: The scale of our war' will remain in place until at least Anzac Day in 2022.
Stephanie Gibson, one of a group of curators for the exhibition, said its success has been beyond her expectations.
"We've seen people in tears and I'm talking about descendants and people that never knew these people... People have been very moved by the stories."
To date, 2.5 million people have visited 'Gallipoli.'
Nearly a quarter of those people were under the age of 25.
The three year extension decision was made earlier this year after around a year of discussion, a Te Papa spokesperson said.
The exhibition was originally planned to close this year but there's still high demand for it from New Zealanders and overseas visitors.
"I think there's a real thirst for knowledge about what happened at Gallipoli, I think a lot of people had no idea and were really amazed to find out," Ms Gibson said.
The stories of eight New Zealanders involved in the campaign and their life-like giant figures created by Weta Workshop are the main attraction.
Ms Gibson said visitors have an emotional connection with the exhibition, and that's why it's different to other war exhibitions.
Over a million paper poppies have been left by visitors at the end of the exhibition area, and curators are now looking at how some of the poppies can be displayed for the long-term in a way that reflects their emotion, a Te Papa spokesperson said.
Handwritten messages left on 3000 of the poppies have been analysed, with an aim to find out the impact the exhibit has had on visitors through common themes like sadness, anti-war sentiment and personal connection.
Researcher Nicola Caldwell said one of her favourite messages was from a child.
‘Dear reader, my great, great grandfather went off to war. He stole his dead brother's birth certificate and got very sick and got injured. What a silly man!’