Children can be detectives, chefs and pilots all in one place while learning and using their imaginations.

The Discovery Cube in Santa Ana has been a hub for teaching through fun since 1998, when it opened as the Taco Bell Discovery Science Center.

On Thursday, a grand opening ceremony was held for the center’s new $25-million, 44,000-square-foot expansion, which nearly doubles its original size and paves the way for more educational and interactive exhibits — and visitors.

“Today, we are celebrating the investment made in our youth,” Joe Adams, the center’s president and CEO, told an audience of about 200, which included council members from Orange County cities, board members and patrons.

“Through this expansion, we’re giving them the gift of science and knowledge and are inspiring them to do more and discover more,” he said.

The growth was a direct response to the nonprofit Cube’s 300% increase in attendance over the past 10 years, Adams said. The Cube gets about 500,000 visitors a year.

Santa Ana Mayor Miguel Pulido called the institution a learning “cathedral.”

“In the beginning, we were looking at a great oak tree seed and thought, ‘How’s it going to ever become a great oak tree?’ This center is like a great oak tree. It has so much wisdom.

“I think as we cut the ribbon, and all these kids come in, their lives are going to be changed. They’re all going to be improved and touched. They’ll have inspiration. This will educate them, and they’ll be able to impact the world.”

One of the biggest additions, Adams said, is the 10,000-square-foot Julianne Argyros Showcase Theater and Exhibition Hall, which makes way for large, traveling, “blockbuster” exhibits.

The interactive International Exhibition of Sherlock Holmes, which puts participants in the shoes of the famed fictional investigator, is the first show in the new exhibit hall.

Children and adults can walk around the room and dig through through clues, matching blood splatters and footprints, for instance, to solve a murder.

At the beginning of the exhibit, which runs through Sept. 7, guests are handed a notebook, akin to the one that Sir Arthur Conan Doyle’s literary creation carried, to scribble thoughts and jot down clues.

Interactive checkpoints, which offer participants the chance to put the pieces of statues back together and record their progress by stamping their notebooks, help them solve the mystery.

The exhibit costs an extra $10 over the $17.95 price of general admission.

A simulated helicopter tour and vector control Inspector Training Course are other highlights of the Discovery Cube’s expansion, which leaves it at a total 115,000 square feet and makes it an even bigger sight off the 5 freeway.

When the doors to the center opened at 11 a.m. Thursday, guests eagerly made their way toward the attractions. One of the most popular was the helicopter tour, where 14 people sit in a room with a giant, 180-degree projection screen. Suddenly, they seem to be airlifted as the simulated helicopter tour takes them through natural landmarks such as Upper Newport Bay and Bommer Canyon.

The simulator is similar to Disney California Adventure Park’s Soarin’ Over California ride. Like its predecessor, the Cube simulator doesn’t move, removing the danger of anyone getting motion sickness.

Adams said he is also excited about the Inspector Training Course, which is presented by the Orange County Vector Control District. The $1-million area allows children to use a touch-screen tablet to go through a scavenger hunt and learn how to coexist with common pests like mosquitos, fleas and rodents.

The Cube is now practicing what it preaches about health. The Bean Sprouts Cafe sits in place of the old Taco Bell, which used to be the only source for food in the building.

The eatery offers such items as healthy sandwiches, fruits and salads.

A nearby culinary kitchen — the first in any science center — also lets children and adults try healthier alternatives to popular foods for free. Children can create a pizza out of watermelon triangles for the bread, strawberries for the pepperoni and pineapple for an extra topping. Fruits are offered in fun shapes to make healthy eating fun.

Adams said the expansion will further the Cube’s mission to inspire and educate youths.

“With this expansion, we’re going to be able to handle the initiatives we set off to achieve,” Adams said. “We’re going to increase science proficiency and promote healthy living and environmental stewardship. That’s what this is all about.”

If You Go:

What: Discovery Cube

Where: 2500 N. Main St., Santa Ana

When: Daily with varying hours

Cost: $12.95 to $17.95

Info: DiscoveryCube.org/OC