The fortress of Hakikino protected thousands of Rangitane people near the coastal community of Waimarama for more than 200 years.
In the early 16th century it was breached by the people of Kahungunu and through marriage the tribes were united.
Hakikino is a sacred place with a limestone grotto that is central to their stories and gatherings but it fell from Māori ownership after WWI.
"The land taken for soldier resettlement, which was all along this area, was because of intense pressure – it was them doing their part for the war effort," Waimarama Maori Tours director Robert MacDonald said.
"I know that my grandmother was never comfortable in losing land in this way – she felt that she had to.
"It upset my grandmother and it was a slap in the face. My grandmother had sent two sons to WWI and neither of them were eligible to go into the ballot for the soldier resettlement farms."
His family bought the land back 40 years ago and a process began to reconnect the people of Waimarama Marae through a tour of Hakikino.
The tour's appeal broadened, eventually becoming an award-winning tourist attraction.
Its success supports a recovery programme, with a native nursery on site.
"The more people know about Hakikino, like anything, the safer it becomes," said MacDonald. "It could have gone over to farmland and the history lost completely. I don't think that is ever going to happen now."