Fifty years ago Tuesday, Queens gave visitors from around the globe a peek into the future at the World's Fair.

Although many of the ideas espoused in Flushing Meadows-Corona Park, including underwater cities and autopilot cars, never came to fruition, historians say the fair helped shape the 21st century. Above all, the event spotlighted the park. And advocates hope this year's anniversary celebration will ensure that light remains bright.

The structures created for the fair "are the essential things that keep the legacy alive," said Matthew Silva, the co-founder of the advocacy group People for the Pavilion, which aims to promote the restoration of the New York State Pavilion, the fair's decaying 227-foot-tall centerpiece.

The years haven't been kind to the steel structure, especially after its red ceiling titles were removed in the '70s. The decay led to its closure 27 years ago.

Silva said the attraction is commonly called an eyesore, but many don't realize its value.

"They are unusual structures, and that's what's unique about the park," he said. "It's not a typical park that has swing sets; it has these structures that are unique and have character."

Silva's group is one of many advocacy organizations pushing for a full restoration of the Pavilion, which would cost $40 million, according to Queens Borough President Melinda Katz. Today, the Pavilion will open for visitors from 11 a.m. to 2 p.m.

From the first video telephone to the latest technology from IBM, the Worlds Fair's displays inspired young people like Bill Cotter, now 62.

A retired engineer and computer programmer, Cotter was 12 when he visited the fair and has since written three books about the 1939 and 1964 events. Many visitors caught the science bug, he said.

"It was so Space Age and futuristic, I wondered, 'How can I be a part of this?' " he said.

Most of the park's infrastructure is still in good shape, Cotter said. The Unisphere, Queens Hall of Science and the newly-renovated Queens Museum of Art are among the period staples that remain centerpieces of the park.

Cotter, who will be giving lectures at the park this week, likened any future restoration efforts to the High Line project.

"Everyone wanted to tear it down and then someone had the idea, no let's just restore it," he said. "What if someone listened to the politicians 20 years ago and tore it down?"

Cotter said he doubts that New York will ever see another World's Fair because the Internet makes it easier for people to share futuristic ideas. But he added that young visitors who check out Flushing Meadows still feel a sense of wonder. And the proposed Pavilion renovation will only further extend a half-century of excitement.

"If you restore it and actually use it and open it up ... maybe some kid will walk in there and have the same sense of awe that me and a lot of people had," Cotter said of the Pavilion.