Sculpture has long been one of the specialties of the William Havu Gallery. Typically, there's a piece or two placed outside the front, plus there's a sculpture garden in the back. Right now, there's even more sculpture on display than normal, as the inside exhibition spaces have been outfitted with 3-D works, too. On the expansive main floor, there's the handsome Three Dimensions, a group show by three regionally significant sculptors; on the mezzanine is David Mazza, a small exhibit dedicated to an important young Denver artist.

In a sense, the sculpture-fest begins with Mazza, because his mild steel sculpture, "Spica," is out on the front sidewalk, and "Hathor" is across the street in front of the offices of Christopher Carvell Architects. (Though it's not part of either of the shows inside, there's also an elegant marble-and-steel piece by Michael Clapper.)

Both Mazzas are signature works in which linear elements precariously balance on diagonal posts that root the pieces to the ground. One of the most interesting things about these sculptures is how they are simultaneously constructivist and expressive.

Mazza has really gotten around during his relatively short career, which began after he graduated from the Rocky Mountain College of Art and Design a couple of years ago. While there, he worked with Erick Johnson, who had also been his high school art teacher. Johnson, of course, is one of Colorado's most important sculptors, and his work is in public and private collections throughout the area.

Mazza's Denver debut was in 2002 at Ron Judish Fine Arts, which was one of the city's premier exhibition spaces until its closure. By 2003, Mazza was in Fresh Art's stable -- another gallery that is long gone -- and in 2004 he joined Havu. This show represents his debut exhibition there, and it comes at the same time that Mazza's sculpture made its first network-television appearance as a part of ABC's hit show Extreme Makeover: Home Edition.

More Mazzas are installed in the Courtyard, which is accessed through an inconspicuous door on the back wall of the gallery. In this section are several pieces that are closely associated with those on the street. Like the ones out front, some of these Mazzas have an arte povera aspect to them. Employing ready-made tubes meant for construction, Mazza leaves the surfaces essentially unfinished, with the welding scars and rust spots standing in for a patina -- and it really works. Other pieces are constructed of scuffed-up stainless steel. In "Set," the two types of material are used together for a gorgeous combination of rusted steel and shiny stainless. Yet another type is finished in airbrushed automotive paint with two layers, a black ground and a puckered metallic paint on top. It is unbelievable.

The last leg of the show is on the mezzanine, and these are mostly smaller works. That makes sense because nobody would want to lug the eleven-foot-tall "Spica" up there. As it is, some of the pieces in this section must have been a nightmare to install. There was surely no problem installing the group of diminutive sculptures displayed on a long shelf at the top of the stairs. These are miniature versions of the large outdoor pieces and actually illustrate Mazza's method, which is to work out his ideas on small sculptures before realizing them on a large scale.

A notable feature of these small tabletop pieces is that they have a luxurious aura. Unlike the pieces out on the street, Mazza painted the miniature sculptures in glossy black automotive paint and then mounted them on rectangular bases made of white marble. They're great.

The three floor sculptures on the mezzanine are also sumptuously finished. Mounted atop truncated pyramid bases are clusters of tubes bent into gentle curves. The first two, "Tefenet" and "Nekhbet," are done in stainless steel, while "Neresger" is painted in a spectacular metallic automotive finish.

I've said it before, and I'll say it again: David Mazza is one of the best artists in the state.

While we're on the topic of Colorado's top talents, the downstairs show at Havu, Three Dimensions, starts off with the work of Lawrence Argent. Born in Australia, Argent earned his bachelor's degree Down Under at the Royal Melbourne Institute of Technology and then came to the states to get his master's at the School of Sculpture at the Maryland Institute in Baltimore. In 1993, he took a job teaching at the University of Denver, where he still works as head of the sculpture department in the School of Art and Art History. Argent has done a number of public sculptures in the metro area, including "Virere," the giant tuft of grass on South Broadway in Englewood; "Pillow Talk," a stack of stone pillows at 20th Avenue and Pennsylvania Street; and "Whispers" an interactive sculpture and sound installation on the DU campus.