Along the Prospect Expressway, inside the ornate Grand Prospect Hall, Alice Halkias talks caviar stations, flower arrangements, and reception themes with soon-to-be brides and bridegrooms.

With wedding season in full swing, the calendar is packed at the century-old Brooklyn catering hall, known for its sweeping, gold-paint-adorned staircase, plentiful chandeliers, and dramatic cable TV commercials, which feature Mrs. Halkias and her husband, Michael, vowing to “make your dreams come true.”

Each year, the Grand Prospect hosts about 800 events, from birthday parties to boxing matches, bar mitzvahs, and about 200 weddings. Many of the nuptials incorporate Old World customs, as the venue attracts brides and bridegrooms of Italian, Indian, and Eastern European ancestry. “The cultural melting pot, it cooks here,” Mr. Halkias said.

After years of buying and selling New York properties, the Halkiases, who live in Bay Ridge, scooped up Grand Prospect “25 laborious and glorious years” ago, as Mr. Halkias likes to say. Since then, the two — known to clients as Mr. and Mrs. H. — have spent thousands of hours and millions of dollars renovating the structure, dressing it up with candy-colored murals, decorative plaster, and new oil paintings created to resemble Impressionist works.

The 140,000-square-foot Grand Prospect has 16 party spaces, among them the Oak Room, a Bavarian-style beer hall with stained glass; a wood-paneled speak-easy lounge, and the lightfilled Atrium, decorated with giant brass sculpture works of roaring elephants. And then there’s the 1,000-person-capacity tiered Grand Ballroom, with a 45-foot ceiling and a colossal chandelier from which a strobe light now hangs.

Making his way through this ballroom, Mr. Halkias stomps his feet and claps his hands, demonstrating the room’s acoustics. “It’s like a Greek amphitheater,” he said. “You don’t need microphones.”

During a two-hour tour of the Grand Prospect, Mr. Halkias shows off his expansive knowledge of the building’s intricacies and idiosyncrasies. He points out the decorative plaster garlands, which he had his staff replicate from wall hangings he purchased in Chicago, and the heavy damask curtains that “Mrs. H. designed.” He calls attention to a German-language sign in the beer hall, which reads, “Come in, Brooklynites, you can’t live on water alone,” and the building ‘s antique but functioning “French bird cage” elevator. “I fell in love with this place. It’s a love affair,” he said.

A Brooklyn developer, John Kolle, opened the Grand Prospect as “a temple of music and amusement” in 1892, though the building was destroyed in a fire seven years later. The French Renaissance-style structure reopened in 1903.

For much of the 20th century, the hall hosted high-profile concerts and conventions and attracted famous and infamous patrons. Al Capone was a regular and is said to have earned the nickname “Scarface” after he was slashed during a brawl in the hall’s speakeasy. More recently, the venue has been the backdrop for such movies as “The Cotton Club” and “Prizzi’s Honor,” and for music videos from the likes of Cyndi Lauper and Foxy Brown.

But weddings and other opulent events are the Grand Prospect’s bread and butter. Prices start at about $115 a person for the catering hall, food, and alcohol.

Bensonhurst native Roxani Fotakos, 31, said she grew up hearing about the Grand Prospect, and it was the only venue she considered for her May 2006 wedding reception. “People our age, mostly they’re going to Long Island catering halls with modern Sheetrock walls, high-hat lighting, and no story,” she said. “But at the Grand Prospect, you actually got to explore the place. All of our guests, even a year later, are still talking about our wedding.”

Mrs. Fotakos and her husband, Aris, 32, have booked the hall for the reception that will follow their baby’s baptism in December.

Among Brooklyn brides Mrs. Halkias is known as a genie of wedding planners, making every attempt to grant the wishes of her clients, whether they want to arrive in a horse-drawn carriage, to be greeted by a quartet of trumpeters, or to be treated to a themed ballet performance during the reception. (All three of the Halkiases’ children were married at the hall, and their daughter’s 1988 wedding reception featured costumed ballet dancers performing “Sleeping Beauty” for guests.)

Neither ballet dancers nor trumpeters performed at the Halkiases’ wedding reception, which took place 40 years ago at the Gregory Hotel in Bay Ridge, now the Best Western Gregory Hotel. The couple recalls saving up to pay the $700 room fee for their 120-person party. “It was much more simple,” Mrs. Halkias said. “Today people are trying to outdo each other. They want a bigger, more unique wedding than their friends’.”