Hapaialii Heiau is a stone temple, possibly used as a calendar, made in the mid 1400’s on the Big Island of Hawaii. A team of masons and archaeologists has restored it one huge rock at a time.

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 southwestern corner of the platformlike structure during winter solstice, and they are expecting it to set over the northwestern corner during this month’s summer solstice.

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

The same team has already begun to restore an adjacent temple which is known as the place where Chief Kamalalawalu of Maui was sacrificed in the 16th century after losing a war to Chief Lonoikamakahiki.

You can see that temple in the background with Hapaialii Heiau in the foreground in this picture: