Whangarei District Council staff and hapu representatives had worked together on the lookout project.
Te Parawhau kaumatua Te Ihi Tito attended Saturday's celebration, 13 years after he was sent on the fated mission to tell councillors that Maori had once and for all had enough of hearing the incorrect "Parahaki" name. He appealed to then-mayor Craig Brown. "He [the mayor] listened. He said, 'I believe you,'" Mr Tito said.
What followed was a racially charged movement against the name reinstatement. But "Parihaka" was officially recognised by the New Zealand Geographic Board in 2005, shortly after which a new reserve management plan required an upgrade of the maunga's facilities.
Mr Tito described the weekend's proceedings as "brilliant".
"I can't believe it, really. This is what it's all about, Pakeha and Maori mixing - it's brilliant."
Mayor Sheryl Mai said the council considered the lookout project as key in acknowledging Parihaka's history.
"This has been achieved through a design that mimics the parapets of the pa that once stood there, with stainless steel panels that describe its history, and a panorama that identifies the locations it overlooks."
Landscape architect Bruno Gilmour had worked on the project and said he was "elated".
WDC's parks and recreation manager Paul McDonald said he was looking at the possibility of CCTV to protect the lookout from vandals. "But at the end of the day we trust people will respect it for what it is," he said.