Lured by a swirling vortex, a young boy ducked under a barrier and bounded into the new, still off-limits Storm Center at the Museum of Discovery & Science in Fort Lauderdale earlier this week.

This was not an uncommon occurrence, said Kim Cavendish, the museum's president and CEO, as she conducted a preview tour.

"It's hard to keep them out," she said.

As of Friday, no one has to stay out of the new $25 million EcoDiscovery Center, a 34,000-square-foot addition to the Museum of Discovery and Science in Fort Lauderdale. Going to the museum will cost a little more, though: Admission increased by $2 earlier this month.

The Friday grand opening will reveal a wing seven years in the making. With a quartet of swimming otters, a simulated airboat ride, a giant megalodon replica and a hurricane chamber, the expansion is heavily focused on environmental issues — and on making the exhibits feel like fun rather than science lessons.

In the Prehistoric Florida section, for example, a large block of ice slowly drips into an aquarium-like tank, creeping up on a beach scene. The representation of climate change is housed in the same section that boasts a giant toothy model of a megalodon or prehistoric shark, Imperial mammoth and saber-toothed cat.

(After getting a sneak peek inside the shark, New Yorker Blake Goldberg, 8, declared: "When you're in there, it feels like you're in a real shark.")

The North American river otters were so entertaining they literally stopped work when they first moved into their new home, Cavendish said.

The four otters frolic and swim in the two-level habitat, including baby Joey, who only learned to swim after handlers coaxed him into water over the course of a couple weeks.

In the Storm Center, visitors can make clouds, view a tornado form in front of them, deliver news about freak weather and step into a booth that produces hurricane-force winds. (Note of advice: Bring a hairbrush to repair the damage, and remove your glasses before entering.)

A simulated airboat ride takes 20 riders at a time through the Everglades with the help of fans, murals and a video.

"What we don't have is swamp gas," Cavendish said.

The walls of the waiting area depict the history of the Everglades, from its draining to restoration efforts.

Also included in the expansion: four classrooms, a science theater and new space upstairs for traveling exhibits. Already in place is K'NEX: Building Thrill Rides, which includes roller coasters, Ferris wheels and other rides made of K'NEX components.

Already, museum officials are looking to the future. With about $5 million, a plot of grass behind the current structure is to become an outdoor science park with full-body interactive exhibits. No timeframe has been set for that plan.

The museum's last major expansion was in 1992, when it moved into the current building and changed its name from the Discovery Center. While the expansion has been planned since 2004, the capital campaign started in earnest in 2007 — and soon ran into the economic downturn.

"The timing was very difficult," said Jon Ferrando, chairman of the board of trustees and an executive vice president at AutoNation. "But it really ended up being a validation of our vision for the museum and our expansion to be able to go out in a very tough economic environment right in the middle of a financial crisis and be able to raise $25 million from the community."