The press preview of the Broad art museum on Wednesday morning might have been the most anticipated architectural unveiling in Los Angeles since Walt Disney Concert Hall was sprung on a breathless public in 2003 on an adjacent plot along Grand Avenue.

And therein lies the rub, for both benefactor and creator. Billionaire philanthropist/collector/development magnate Eli Broad, who footed the $140 million bill, acknowledged the quandary to the assembled: “How do you design a building that doesn’t clash with Frank Gehry’s masterpiece, but also is not anonymous?”

And Elizabeth Diller, the new museum’s lead designer, mentioned the “daunting” presence of her building’s neighbor to the north. “How do you build next to that beauty?” she asked rhetorically. “We got over it pretty quickly. And we realized that we really couldn’t compete. What’s the point? We had to be true to our program. We opted for a relationship of contrasts to our neighbor: porous and matte next to smooth and shiny.”

The honeycomb-like structure (covered by fiberglass-reinforced concrete panels), which opens Sunday, joins an impressive array of landmark buildings designed by notable architects on Bunker Hill that include the Disney hall’s undulating form; MOCA and the Cathedral of Our Lady of the Angels.

As both Broad and Diller pointed out, the project took just five years from concept to reality (versus Disney Concert Hall’s nearly 15-year construction). And for Diller, the biggest challenge was meeting two different mandates that seemed mutually exclusive: “to make a building that could contribute to the urbanization of Downtown L.A. i.e., public, transparent, open; and yet the largest part of the program was the storage facility.” She referred to the two-pronged process as “the veil and the vault.”

The middle-floor vault holds the collection of some 2,000 works — 250 of them on display in the first- and third-floor galleries; and the veil is described by Diller as “a somewhat coy and porous mineralite five-sided facade, with certain characteristics of coral, and sometimes sponge.”

L.A. Times architecture critic Christopher Hawthorne called it “a surprisingly punchless facade.” But, as Hawthorne pointed out, once inside, the space comes to life, especially in the museum’s literally cavernous lobby, with walls covered in Venetian plaster, and womb-like escalators that ascend to the sunlit main exhibition space that crowns the Broad.

The museum’s theme might be “Art of Our Time,” and Broad’s collection certainly makes a strong case for the importance of such contemporary L.A. artists as John Baldessari and Ed Ruscha, as well as such modern and pop icons as Jasper Johns, Cy Twombly, Sam Francis, Robert Rauschenberg, Andy Warhol and Roy Lichtenstein.

The New York art world of the 1980s is also on prominent display: Cindy Sherman, Barbara Kruger, Jean-Michel Basquiat and Jeff Koons, to name a few.

It’s a highly concentrated and keenly curated collection that, as Joanne Heyler, founding director of the Broad and associated with Eli and wife Edye for some 25 years, says, reflects the Broads’ “clear and unwavering commitment to two things: to artists and to connecting art with the public.”

Admission is free, after all, and the public has already responded in droves to the tune of more than 85,000 tickets booked in advance. And those behind this new Downtown destination are hoping this will add dimension to the assertion that L.A. is the contemporary art capitol of the world.

As L.A. mayor Eric Garcetti stated at the press conference, the city represents more than just Hollywood glamour: “We hope you will get into the guts of this building because it takes a few visits to understand and to feel how it both reflects a place where we always (present) a beautiful face to the world — we’re Los Angeles — but also deeper meaning the more you get to know us and the more you get to know the city.”