The Central Garden at the Getty Center in Los Angeles is not just a collection of plants but a complex sculpture by contemporary artist Robert Irwin. Set like a jewel within the Getty Center’s imposing promontory overlooking Los Angeles, Irwin’s work is a critical element in Getty’s collection of contemporary art.

This year is the Center’s – and the garden’s – tenth anniversary year. It should be high on any art-and-garden lover’s list of places to visit in 2007. This garden sculpture may well prove to be the signature piece of American landscape art of the 21st-century in the manner that Fletcher Steele’s ‘Blue Steps’ at Naumkeag marked the 20th, and Calvert Vaux and Frederick Law Olmsted’s Central Park delineated the 19th.

Most everything about this piece of art will subvert expectations. Let’s start with the artist himself. Irwin is not: a landscape architect, a garden designer, or even a gardener. I’ve learned over the last year and a half (I have visited this garden perhaps 50 times) that many (not all, of course) gardeners can be, well, a bit reactionary. Even professional garden writers, horticulturists, and garden historians (all of whom should know better) will dismiss this work of art (after a 15-minute flying visit) on the grounds that “it isn’t really a garden in my definition,” or “for heaven’s sake, all those azaleas baking in the sun.”

Irwin is, or has been, on the other hand: an early abstract expressionist; a minimalist; a painter, a sculptor; an installation artist; and an artist of what is called by some “the articulation of space and light.” His life as a working artist – some fifty-plus years, as he is in his eighties now – has been one of constant personal and aesthetic reinvention. What he came to is this: Art is pure perception. We, the experiencing viewers, are therefore implicated, and included – if we abandon prejudice to clear the doors of our own perceptions. Irwin may work at the Getty with Cor-Ten steel, and boulders, rocks, stone and pebbles, brass and teak and water and plants, but it is up to us to shred our preconceptions to enter into what is really not a place, or a garden, in a conventional sense, but an ever-changing experience.

The Central Garden of the Getty Center is set among the white, unified village of imposing, linear buildings designed by the internationally celebrated architect Richard Meier. His geometry marks the definition of the Getty Center. The high white travertine-clad village, a stunning addition to the architectural treasure-trove of contemporary Los Angeles, can be seen for miles – well, on a clear day.

The Central Garden is the counterpoint to the straight lines and rational approach of Meier’s cubes. The garden, in contrast, zigs and zags and curves and circles, and even shocks with layered color and texture and form.

A walk through the garden is a kinesthetic and sensual experience. The “sculpture” is essentially in three parts: the first is called the stream garden, where a visitor begins walking down a slope to what looks like the terminus of the garden and a sweeping vista of Los Angeles. The stream garden is essentially a canyon of tumbling green chert boulders sliced by running water, and punctuated with – now remember this is Los Angeles, USDA Zone 10 – large deciduous London plane trees (Platanus x acerifolia ‘Yarwood’), employed as almost abstract elements. (It’s not that Irwin just “liked” these plane trees. He studied how they looked lit in front and back; he considered their effect on color in the garden, in leaf and bark – and also their density, and form.) Visitors walk in a zigzag pattern down the canyon, on a stone path laid in herringbone design. When the stream is crossed, teak planks repeat the herringbone of the stone. This is not even to mention the plants, or the sound of water, the smell of flower and leaf, or the boulders giving way to smaller rocks and then to an elegant pattern of stone in the waterway.

The stream garden spills out to a second overlook, a transition space, or plaza, marked by seating areas with umbrellas of bougainvillea and metal fifteen feet overhead, the bougainvillea tumbling out of bouquets of the unexpected – industrial rebar.

It’s now that you see what you couldn’t see before. Follow the sound of water and peek over a carnelian granite wall to see the stream plunging 20 feet into a pool of water surrounded by what is called the bowl garden. The oft-discussed and controversial azalea maze is set into this pool (they do seem to bake in summer, but never mind).