Rome’s new MAXXI museum -- the XXI stands for "21st century," the MA for "museum of art" -- is so grand that I think we missed a floor on our first visit. Designed by deconstructivist architect Zaha Hadid (via a scribble, Roman wags say, that was interpreted by master engineers), the three-story, warehouse-sized facility is sited in the relatively ho-hum northwestern sector of Rome’s central city, behind a modern ornamental gate on a spacious plot landscaped with alternating swaths of concrete and white pebbles.

At the MAXXI entryway, the museum looms over the visitor like a concrete bunker after an earthquake, its asymmetrical masses held up with rows of slim silver columns, a curious architectural accent that brings organ pipes to mind. Inside, the swooping interior spaces are remarkable and strange but not bewildering.

The museum’s overall plan curves like a hockey stick, and rarely involves closed galleries that are entered via doors. Rather, the exhibition halls are divided into irregular open levels and volumes connected by forking stairs, stepped spaces and walled ramps, offering long vistas on both horizontal and vertical planes.

Thanks to all this swoosh, the place seems more like a set for an action movie than a place for the contemplation of art. But the art comes out well, once you look at it instead of the architecture.

Welcoming the visitor is a retrospective of works by the mysterious metaphysician Gino De Dominicis (1947-1998). On the museum plaza lies a huge, prone skeleton of one of his signature bird men (identifiable via its bony beak), a kind of esthetic alien descended from those of Max Ernst and Giorgio de Chirico. Inside, the De Dominicis show continues through the lobby (whose information desk boasts Hadid’s trademark marshmallow biomorphism) and proceeds up a zigzagging black stairway, via two or three portraits of his bird man, and then disappears up an elevator (to the gallery, not an entire floor, that we missed).

Further in the rear on ground level is a second retrospective, this one devoted to an enchanting installation of architectural models and photographs from the workshop of Italian modernist Luigi Moretti (1907-1973).

But most of the sprawling museum is filled with "Spazio," an exhibition from the collection. Despite the title, only a few of the works involve the notion of "space." More importantly, the show announces MAXXI’s claim to be a Roman stop on the global art tour, including works by Francis Alÿs, Ilya and Emilia Kabakov, Anish Kapoor, William Kentridge, Anselm Kiefer, Kiki Smith, Andy Warhol and everyone else who typically populates such institutions.

Indeed, in its May issue, the Italian magazine Arte carefully weighed the relative importance of Italy’s cities in terms of the art world, and found that Rome is now on top, superseding Venice, with its biennales and new François Pinault-spawned Punta della Dogana, and Milan, which has long been Italy’s art-gallery center.

And how are Italy’s own artists treated by "Spazio" and the museum as a whole? Rome’s artistic community, which thought MAXXI would never be finished (the museum has suffered ten years of fiddling and delays), is needless to say split on the matter.

Many locals are included, with works ranging from Arte Povera to Maurizio Cattelan’s serious Ninna Nanna (1994), a dense canvas bag of debris from a terrorist bombing. But other Roman artists are not, notably those who staked Italy’s own glorious claim to artistic fame in the 1980s, when it felt like contemporary art was first going global with a vengeance.

For instance, the show features a triumphant series of 24 large photos by Luigi Ontani representing the hours of the day, but has nothing by the "Three Cs," Sandro Chia, Francesco Clemente and Enzo Cucchi.

This is a shame. Parochial though the sentiment might be, I wish the museum had launched with a survey of the specifically Italian contributions to the postmodernist period. On the other hand, "Spazio" introduces many Italian artists, like Lara Favaretto, Maurizio Mochetti and Grazia Toderi, who are less familiar on the international scene. We can cartainly expect MAXXI to serve as a launching pad.

A few caveats. The outdoor plaza, which is only out the door from the museum’s own coffee bar, desperately calls out for café tables and chairs, to bring the sun-drenched flat to life in true Roman style. And MAXXI’s handsomely dressed young guards (in black paints and white shirts) spend way too much energy telling museum visitors that photos are forbidden. Really, these bans are ridiculous.

Still, as absurd as it may seem to add a contemporary art museum to your Roman itinerary, MAXXI is definitely worth one visit, and is likely to prove confounding and rewarding enough to provoke a few more. It’s the beginning of a new era.

WALTER ROBINSON is editor of Artnet Magazine.