Lucy celebrates a birthday Friday. Her 120th.

That the country's most celebrated elephant lasted this long is testament to the tenacity of her owners, the good fortune to survive coastal storms and grass-roots efforts by Margate residents. Their work even resulted in Lucy's designation as a National Historic Landmark, one of only 2, 329 in the country.

``She is the only one like this in the world,'' said Richard Helfant, executive director of the Save Lucy Committee, which operates the attraction.

She's certainly the only fabricated animal designated a national landmark, said John Sprinkle, a historian for the agency that approves such designations. She contains 4 tons of bolts and 12,000 square feet of tin; each ear weighs 2, 000 pounds.

The elephant was built in 1881 by Philadelphia-born engineer and inventor James V. Lafferty Jr. as a promotional gimmick to sell land in what was then called South Atlantic City. The six-story pachyderm has served as a hotel, tavern, real estate office, home and tourist attraction in her 12 decades of life.

On Friday, the public is invited to Lucy's birthday party, which runs from 10 a.m. to 5 p.m.; it will feature balloon and T-shirt giveaways and birthday cake. A local radio station will broadcast live from her howdah (the seat on her back) between 2 and 4 p.m.

Almost 20,000 people visited Lucy last year.

``We hope to grow those numbers substantially," Helfant said. "We're not even scratching the surface."

Josephine Harron, who formed the committee to salvage the elephant after it deteriorated over time, says Lucy's popularity stems from her uniqueness.

``No one else has a six-story elephant you can walk through and come out alive,'' she said. ``Little children stand with their mouths open, saying, `Oh my goodness.'"

To date, Lucy's restoration by the committee has exceeded $1.5 million. Plans call for an addition to the gift shop to house a museum, with artifacts and other mementos from her past.