For New Zealand forward Tamaiti Williams, a visit to a First World War cemetery ahead of the Rugby World Cup in France provided an unexpected and emotional link to his family heritage.

The squad visited the official New Zealand military cemetery at Longueval, known as Caterpillar Valley, outside Arras. They also went into the tunnels dug by the soldiers.

"It's been pretty overwhelming," said Williams. "I found out my great, great grandfather served in those tunnels. That was a pretty special moment for my family."

Williams said he had posted about the visit on social media.

"My grandmother got my auntie to text me and send a few pictures. It was pretty cool to be down there where he was."

"Down there, you feel how hard it must have been."

"When I got back to my room, I had a little tear with my mum. It came out of nowhere." "No one in my family's been to France and for me to see with my own eyes where he was was special."

"I'm from a small place in New Zealand and for my great, great grandfather to do that, this far across the world, it gives me a good image of who I am and where I come from."

The 23-year-old, who is from Whangarei north of Auckland, made his All Blacks debut against South Africa in July.

'BIGGER THAN RUGBY'

"To know you have men in the team who have ancestors who were involved in such a special, devastating, tough place to be, it really gives you a connection to France," said hooker Codie Taylor.

"What they did was so much bigger than rugby, but they went for their nation to do something. We're on the same mission in sport and in rugby."

At Longueval, the All Blacks laid a wreath for Bobby Black, a former New Zealand rugby international, who died in the Battle of the Somme.

They also performed a haka, but Taylor, who like Williams has played for the Maori All Blacks, said it was different from a game-day challenge.

"That one was more around the connection in our heart and our soul....as Maori connecting back to those men that are laid there at rest and the men that are still missing with their names on the wall. It was a chance to honour them and for us the haka is one way we do that and pay our respect to the men who fought and the All Black on the wall."

"The haka when we're in Stade de France is all about battle and connecting us as a team the buzz is a little different you're giving your all because you're about to go to war."