SEATTLE - Fifty years after the World's Fair inserted the Space Needle into Seattle's skyline, the city is celebrating that anniversary by offering an array of new things to see and do at Seattle Center: from a zip line to a new art glass museum.

Seattle's 74-acre gathering place has been gradually reinventing itself for years, with a new opera house and a rock 'n roll museum designed by Frank Gehry.

This year's changes may be the most dramatic since the Experience Music Project opened in June 2000. The rides and games that have been around since 1962 have all but disappeared. Glass art, a sophisticated new restaurant, history displays and a temporary playground filled with blow-up toys have taken their place.

Beyond the connection to the World's Fair, Seattle Center isn't easy to describe. If it were in New York City, for example, it might be described as a cross between Lincoln Center and Central Park, but with a lot fewer trees.

It's a large park, filled with public art and grassy picnic areas and home to more than 30 arts and cultural organizations. The 220-foot wide International Fountain, which shoots musically choreographed water from 137 nozzles as high as 120 feet into the air, is its most popular attraction, especially on warm summer days.

"We're going to try to touch the fountain without getting wet," said Mark Kleisath, a visitor from Walnut Creek, Calif., who was in town to see his daughter get her Ph.D. from the University of Washington. They stuck to free activities at the center, including stopping by the EMP to see how the Space Needle reflected in its metal exterior.

Including the EMP, four museums are scattered around the campus, from the Pacific Science Center to the Bill & Melinda Gates Foundation's new visitor's center and the Children's Museum. Sports teams, movies and rock shows make regular stops and the city's biggest festivals all take place at Seattle Center.

Not all this fun is free, however, including the beautiful but pricey new glass art exhibit, Chihuly Garden and Glass. You could just peek over the hedge at the garden, but you'd miss some of the coolest installations including one of Dale Chihuly's mesmerizingly bright glass ceilings and an unusually shaped glass house that seems destined for wedding receptions.

Families with young children might want to skip the exhibition and go straight to the restaurant filled with Chihuly's personal collections of toys and other objects. Some will leave the Collections Cafe with a free booklet chronicling Chihuly's collections of old radios, ceramic dogs, bottle openers, etc.

Of course, it might be fun to see if your toddler will try to crawl into the displays. Leslie Jackson Chihuly isn't worried about breakage because she says her husband's work has traveled around the world but is seldom broken by overeager art patrons. She expects the little ones will really enjoy the bright colors.

The Chihulys are hopeful the exhibit right under the Space Needle will attract thousands of new visitors to the center.

Some people protested the idea of adding a new commercial venture to the campus, but Seattle Center director Robert Nellams says it's important to find the right balance between free events and attractions that generate revenue.

The Seattle City Council doesn't have extra money to pump into the place. City tax dollars already cover about 35 percent of Seattle Center's about $35 million annual budget.

The zip line, which costs $7.50 to ride, was added to answer criticism when the fun forest was removed. It's part of an area called "playway." Here's some Seattle Center trivia to store away: the area of rides and games was called "gay way" when it opened during the World's Fair.

For more trivia and historical facts about the World's Fair or Seattle Center, stop by the history exhibits that are part of the 50th anniversary celebration.

"There a lot to see and do here," said Brenda Tubbs of North Bend, Wash., who brought family visiting from Utah to Seattle Center. They checked out the Children's Museum, the Space Needle and the International Fountain.

Tubbs, who was carrying one grandchild and keeping an eye on two more, said she'd like to see the Chihuly exhibit but, "I can't go in there with three little ones. It's not really compatible."