KEAUHOU, Hawai'i — A piece of Hawaiian history has been restored, one rock at a time.

Hapaialii Heiau, a stone monolith lying on the Keauhou shoreline, is believed to have once served as a calendar. It is the first of several ancient temples and sacred sites along the shore scheduled for restoration by Kamehameha Investment Corporation Inc., a for-profit arm of Kamehameha Schools.

"The purpose of this restoration is to make these sacred sites the anchors, the icons, the symbols, essentially the platform for establishing a cultural presence on this land," said Greg Chun, corporation president. He said the existence of 10 to 12 sites in the area shows that ancient Hawaiians felt it was a very special place.

"Where a site like this is resurrected out of the ground, the land starts to look and feel different," Chun said.

Hapaialii Heiau and the adjacent Keeku Heiau, currently under reconstruction, sit on the rocky coast between the Outrigger Keauhou Beach Resort and the site of Kona Lagoon Hotel, which was demolished in 2004.

Carbon dating indicates Hapaialii Heiau was constructed between 1411 and 1465. The restored temple measures 150 feet by 100 feet and is surrounded by water at high tide.

The restoration team was composed of archaeologists, cultural practitioners and Hawaiian experts in dry stack masonry.

The team used measurements and research from 1906 maps of the inner wall and 1952 maps of the outer wall.

Historians believe it took thousands of commoners a decade to maneuver huge rocks into place and construct the platform.

Master mason Billy Fields and his three-man crew, with the assistance of modern machinery, took four months to recreate the heiau.

"The engineering is already done," he said. "It's not written in books, but my advantage is I get to take it apart. We already have the rocks, so I have the easy part."

The team began moving stones July 25 and finished in December. With the exception of the finishing layer, stones used in its restoration were recovered from the surrounding area.

During the project, it was discovered a person could accurately mark the passing of the seasons when standing behind the center stone on the heiau's top platform and aligning it with various points on the heiau.

Experts found that the sun sets directly over the southwest corner of the platformlike structure during winter solstice and they are expecting it to set over the northwest corner during this month's summer solstice.

"Our ancestors were well accomplished developers," Chun said. "A lot of knowledge was revealed through this work."

Chun said the restoration project will launch education programs geared not only to student assistants who earn class credit, but to visitors who want to soak up some Hawai'i history with their sunshine.

"We look at assets like this as the foundation for education programs that will capture, preserve, document and teach cultural practice," he said. "Hopefully, students discover some things about themselves and even some career opportunities they hadn't thought about."

A program for visitors still is under development.

"Our ancestors chose to live and build in this place for very special reasons," Chun said. "We know what we're doing won't be marketable to everybody, but it will be uniquely tied to stories of this land."

Work has begun on restoration of the adjacent Keeku Heiau, where invading Chief Kamalalawalu of Maui was sacrificed after being defeated by Chief Lonoikamakahiki in the 16th century.

Long-term plans include identifying and researching cultural and historical sites within 100-plus acres of archaeological preserves found in Keauhou, about six miles south of Kailua, Kona.