It's amazing how far $21 million and nearly four years of work will go to help a graying museum regain some of its former luster.

A full-size model of a sperm whale used to be the "wow" attraction on display at Bishop Museum's Hawaiian Hall.

Now, the refurbished hall itself, which will open to the public tomorrow for the first time since 2006, will likely give the whale a run for its money.

One step into the museum's great hall and the changes are immediate, appealing and invigorating.

The once-stuffy hall is now air-conditioned, and gone is the "spray-and-wipe" institutional white paint that once covered the museum's structural support columns, walls, windows and skylights.

Re-emerging are the miles of highly polished koa wood that, when coupled with hundreds of indirect lights, give the hall a warm, rich appearance.

"The lighting now is very subtle," said DeSoto Brown, manager of the museum's archives collection. "It creates points of interest — it's a little more theatrical, a little more dramatic."

Dozens of alcoves with interactive displays on each of the three floors feature Hawaiian artifacts that help tell the story of a culture that flourished, then ebbed and flourished once again. Many of the artifacts have never been on display.

"The display cases are filled with implements that Hawaiians used in their everyday activities," Brown said. "The interactive features use still photos, movies and quotes from people from the 19th and 20th centuries talking about their culture."

A committee of five people met for four years deciding what items each of the showcases should feature, where each should be located, what should be said about the artifacts and how the information should be conveyed.

"We want people to learn, to be informed, to come away with a knowledge of Hawaiian culture that they didn't have before," Brown said.

The museum's first floor now features the realm of Kai Akea, representing Hawaiian gods, legends, beliefs and the world of pre-contact Hawai'i.

The second floor, Wao Kanaka, represents the realm where people lived and worked, focusing on the importance of land and nature in daily life.

The third floor, Wao Lani, portrays the realm inhabited by the Hawai'i gods and provides exhibits on the ali'i and key moments in Hawaiian history.

The whale remains suspended from the same corner of the ceiling but is now joined by a number of other creatures including a manta ray, turtle, seabird, two ulua captured in a powerful mid-turn and an 18-foot tiger shark.

An elevated stage that once dominated the middle of the atrium floor has been removed and replaced by an exhibit that features two huge ki'i, or carved wooden figures, that pay tribute to ku or Hawaiian gods.

A hale pili, or grass house, has been completely refurbished and moved to floor level from the platform it sat on for years.

Students in the Hawaiian Academy program at Farrington High School worked for two years to restore the grass hut. The students stood in front of their completed project yesterday and performed a chant while many of them beamed at the result of their hard work.

"They made two trips to Mauna Kea on the Big Island to gather the pili," said Kalei Napuelua, the students' teacher at Farrington.

They took apart the 109-year-old hale pili, repaired the existing 'ohi'a timbers and used eight miles of cordage woven from plants to attach the hut's cross members, and to anchor bundles of the new pili thatch, Napuelua said.

Poomaikai Crozier, a skilled craftsman from Maui, helped guide the students.

"He's a relatively young man — 38 years old — but he learned these traditional techniques from his father," Napuelua said.

Students Leialoha Ngaue and Charity Tuiloma, both Farrington students, estimated that they worked five to eight hours a week over the past year helping to rebuild the hut.

"It was really cool, but hard work," said Ngaue, with Tuiloma nodding in agreement.

The two said they hope to return 50 years from now to show the museum exhibit they worked on to their children or grandchildren.