Near Hawaii Kai Drive overlooking Koko Head, scores of volunteers are pulling weeds, digging up old fence posts, and turning shrubs into mulch to help to bring back a Hawaiian heiau and a section of wetland that was part of an immense fishpond that stretched to the ocean.

"It is the piko (center) of this area," said Kaleo Paik, cultural adviser to Livable Hawaii Kai Hui. "We were able to save it."

With assistance from the Trust for Public Land, the hui was able to acquire the 5 acres from an adjacent developer who had planned to use the parcel for condominium amenities, including a swimming pool and tennis court.

The volunteers, including families, worked Saturday on a project called "A Day on the Land," organized by the Trust for Public Land.

More than a 100 people from more than a dozen firms served as volunteers.

The parcel is home to the Hawea Heiau and remnant section of the Keawawa Wetland, a portion of a 500-acre fishpond that extended to the ocean.

Some say the fishpond was the largest in the Pacific.

According to oral histories, Hawea was the name of a huge drum introduced by visiting Tahitian chief Laamaikahiki. Paik said she believes the complex once housed Hawea.

At a high point on the parcel are remnants of a stone platform of the heiau.

As the brush is cut away and rocks of the former heiau are uncovered, Hawaiian cultural specialists are learning more about the Hawea Heiau and Keawawa Wetland Complex and adjacent areas, including the fishpond.

The wetlands, fed by springs, are home to a number of endangered species, including the alae ula, or Hawaiian moorhen; the aukuu, or black-crowned night heron; and the Hawaiian dragonfly.

The fishpond, which included mullet, "fed thousands of people," said Laura Ka‘akua, the native lands project manager with the Trust for Public Land. Questions remain about how the fishpond was operated and maintained. "We don’t have all the answers, but we’re trying to piece together what is left."

Part of the answer is building support for restoring the complex through hands-on education.

Several children whose parents were volunteers held onto a leaf of a newly planted loulu palm during a blessing.

"We like coming to events that are hands-on," said Stephanie Sakurai, a Hawaiian Electric Co. employee who attended the event with her family. "It’s important for them to learn, participate and give back to the community."

Livable Hawaii Kai Hui President Elizabeth Reilly said with help from various sources, the group has been able to remove some 365 invasive species.

For more information, go to www.hawaiikaihui.org.