For tourists, a luau is a must-do. For Hawaiians, it's so much more.

• Modern luaus are celebrations with food and entertainment, but they originated from the 1819 abolishment of the kapu system.
• Many commercial luaus feature Pan-Pacific performances, while authentic Hawaiian hula was traditionally more ceremonial.
• A traditional luau feast often includes food like a whole pig slow-cooked in an underground oven called an imu.

MAUI and HAWAII ISLAND, Hawaii — As the sun dipped below the horizon, the hula dancers took to the pa hula (hula mound) against the rhythmic pounding of the ipu (gourd) and pahu (drum). Dancing with intention and grace, their body movements told the moolelo (story) behind one of Hawaii's most beloved endemic flora.

According to Hawaiian mythology, a warrior called Ohia and his lover Lehua lived blissfully in the forest until interrupted by Pele, the Hawaiian goddess of fire and destruction. The dancer as Pele is draped in layers of lei woven of maile leaves and with lei poo (flower crown) atop her head. As legend goes, Pele tried to steal Ohia away, but he refused her advances. Upset, she trapped the couple in a ring of fire and they were transformed into the now-endangered ohia lehua tree famous for its vibrant blossoms.

Like this performance, the rest of the Old Lahaina Luau's show is as captivating as it is educational – and also unapologetically Hawaiian, as it's been for the last 40 years. The show traces Hawaii's history, from the arrival of the first Polynesian settlers to the missionary colonizers publicly banning hula, culminating with the cultural practice once again being celebrated in the islands.

For many travelers to the Aloha State, attending a luau like this one is a must-do. It's not difficult to find a luau show at most resorts, but it is hard to find one that's authentic.

Based on what's been shown in the media, most visions of a luau are not entirely Hawaiian but more Pan-Pacific. People imagine being wowed by fire performances (that's Samoan) and fast-paced, hip-shaking dancing with those big eye-catching headdresses (most likely the Tahitian otea dance).

Kawika Freitas, director of public and cultural relations at Old Lahaina Luau and a Native Hawaiian cultural practitioner, told USA TODAY:

What happens is some people need or expect the performance to be loud, flashy with colorful costumes, but if you look at our ancient Hawaiian ancestors, and when they performed, the hula was never like undefined the old days, it was more religion, it was more in temples, it was more genealogy and honoring gods, honoring people, honoring events. So they never needed all of that flash.

Here's what travelers should really know about luau in Hawaii.

What is a real Hawaiian luau?

Going to a luau is nearly synonymous with visiting Hawaii, but the modern-day version we know it as today isn't what it's always been. Even locals use the term "luau" to describe a party for a joyous occasion, such as a baby's birthday or graduation.

"Luau (now) is a celebration with food, entertainment, everybody just coming together and enjoying each other's company," said Freitas. "In ancient days, these kinds of celebrations did not happen."

That's because of the kapu system, the pre-Western contact law system, where people abided by regulations to not upset the gods, like men and women not being able to eat together. If you broke a kapu, you were punished – sometimes with death. At the time, hula wasn't seen as entertainment but as a ceremonial practice, mostly reserved for men.

Some consider the first luau to have taken place in 1819, when King Kamehameha II ate with his stepmother, Queen Kaahumanu, on Hawaii Island, marking the end of the kapu system and ushering in an era of Christianity. From there, people could eat and celebrate together, and public luau and royal gatherings were held. It wasn't until the latter half of the 20th century that commercial luau started operating.

How does a luau work?

At the Old Lahaina Luau, the process is not rushed. All elements are intentional and pay tribute to Hawaiian culture, like having traditional Hawaiian seating on the ground. The show includes kahiko hula, which is more traditional, with chanting and percussion, before transitioning to auana, the modern style with music and dancing. (There is Tahitian dancing with the vibrant costumes, but to represent the first Polynesians to settle in Hawaii, likely from the Marquesas Islands or Tahiti.) Since 1986, little has changed in the programming, Freitas said.

Becoming a hula dancer for Old Lahaina Luau can be an intensive process, with training of up to three months, including internal video recording and one-on-one sessions with a lead dancer. Dancers wear lei and ti leaf skirts, made from real plants and are kept refrigerated when not onstage to last up to three weeks.

Besides entertainment, people come to a luau for the food – a feast combining Hawaiian and local fare brought by the immigrants who came in the 19th and 20th centuries to work on the plantations. Dinner begins with poi, haupia (coconut pudding), pohole (fern) salad followed by other traditional Hawaiian dishes, like kalua pig (shredded pig cooked in an underground oven, or imu). More American food, such as grilled steak and fish, is also served, but strategically after people have hopefully filled up on the island cuisine.

Most luau also include revealing the imu, a traditional underground oven that slow-cooks a whole pig and other foods, such as sweet potatoes, over the course of hours. This is the way Hawaiians have cooked for centuries.

At the Island Breeze Luau at King Kamehameha Kona Beach Resort in Kona, Hawaii Island, the imu is prepared by the Men of PAA, a Hawaii Island nonprofit rooted in cultural preservation, in a nearly all-day affair. Starting at around 7 a.m., they dig and heat up the imu before butchering the pig, and burying it under banana leaves to cook until tender. About 10 hours later, at around sunset, the imu is finally opened to showcase an entire pig ready to feed luau guests.

How to identify an authentic luau?

Here are some characteristics of an authentic Hawaiian luau:

• Aspects of the luau are rooted in Hawaiian culture, such as hula accompanied by the traditional percussive instruments and authentic cuisine. "One of our biggest complaints is that we don't have a fire knife dancer," Freitas said. "It's not like we don't want to pay a guy to do it, but we're just trying to provide something that's very unique and authentic – and that's what sets us apart." Shows may incorporate some other Polynesian traditions, but still tie it back to Hawaii, like how the Old Lahaina Luau opens with a Tahitian dance to represent the Polynesian settlers who arrived in the Hawaiian archipelago.
• Performers aren't in over-the-top, flashy outfits perpetuated in Hollywood movies, but honor traditional hula attire. In ancient Hawaii, dancers wore simpler clothing made of kapa (barkcloth fabric) and shell and leaf lei, not only around their shoulders but also lei poo (lei atop the head) and kupee (lei around ankles or wrists). They might also wear clothing that pay tribute to more contemporary Hawaiian history such as long dresses (muumuu).
• The stories being told focus on Hawaiian legends and history. They also give guests a sense of place, educating them about the Hawaiian Islands and even the specific ahupuaa (land division) they are on. At Old Lahaina Luau, the announcer shares about Lahaina's Lahainaluna High School, established in 1831 and considered to be the oldest school west of the Mississippi River.

Perpetuating culture through luau

For many Hawaiians, a luau is more than just entertainment, and preserving the cultural tradition carries a deep significance. Native Hawaiian Iopa Maunakea founded Men of PAA in 2006 to help hundreds of men reintegrate into society and rediscover their identity after being in the justice system through a connection to culture. "They're engaging, they're buying into the whole idea that we need to connect to our cultural traditions so that we can manifest it in today's society," Maunakea told USA TODAY.

In a process he calls hookanaka (to be a leader), the men not only learn about Hawaiian values but also how to live them out while gaining work skills on Maunakea's Hawaii Island farm. "When a man gets good, his family gets better and when the family gets better, who benefits from that? Our community members," he USA said.

Under a joint organization called Imu Mea Ai, Maunakea and his men host bi-monthly hands-on workshops on the farm for guests to build an imu using skills passed on to him from his family, and culminate with a feast. While tourists are the main guests, there are also some workshops specifically open to the Hawaii Island community, including hosting schools.

"It's really about preserving our Hawaiian culture, stewarding our lands," he said, adding that it's also about making an impact on the community and to inspire better tourists. "They got a good burst of culture, they got it very, very immersive and they got it right from the source."