The work of the American sculptor Richard Serra (b. 1939) is infamously confrontational. That provoking spirit is very much alive in “Richard Serra Sculpture: Forty Years” — a slow-building yet ultimately gripping retrospective of 27 of the artist’s sculptures from between 1966 and 2006 — which opens Sunday at the Museum of Modern Art. Much of the early work from the 1960s involves bits of scrap iron, wood, or weatherized rubber strewn seemingly willy-nilly across the walls and floors, or extremely heavy, tenuously propped or balanced pieces of lead that threaten to topple like houses of cards. His signature sculptures from the last 30 years are made of large, long, leaning steel planes. Their 15-foot-high spiraling walls, weighing nearly 200 tons, loom precariously overhead like rusted ship hulls; and they lure viewers inward with their seductive curves, to envelop them within vertiginous, at times claustrophobic, labyrinths.

Mr. Serra’s sculptures — one of which at MoMA is titled “One Ton Prop (House of Cards)” (1969) — can make viewers feel ill at ease: In 1988, while dismantling a 16-ton Serra sculpture at the Leo Castelli Gallery, a worker lost his leg when the artwork collapsed. While installing one of Mr. Serra’s sculptures at the Walker Art Center in Minneapolis, in 1971, a rigger was killed when a 2-ton plate fell on him. And Mr. Serra’s federally funded site-specific sculpture “Tilted Arc” (1981) — a curving steel band 120 feet long and 12 feet high that cut New York’s Federal Plaza directly in half — was dismantled and scrapped, in 1985, after years of complaints that culminated in an angry public hearing. The sculptor, in defense of “Tilted Arc,” remarked: “I do not think it is the function of art to be pleasing. Art is not democratic. It is not for the people.”

Mr. Serra certainly is not incorrect: Art, which speaks as much to other art as it does to viewers, does not give a damn if the spectator is incapable of receiving what it has to say. And yet at their best, Mr. Serra’s monumental sculptures are extremely democratic: They may begin confrontationally, but their hulking, extroverted bodies provide inward and intimate spaces.

All art worth its salt is challenging, but not all challenging art is worth its salt. By that I mean that the give-and-take between spectator, or participant, and art needs to be demanding. Otherwise, the engagement is not worth the time. But art needs much more than shock value. The experience of art is not one in which the artwork sits still and the viewer contemplates it from a distance: Rather, it is a relationship between living beings. Art plants itself inside of us. It grows and changes as the viewer’s perception changes. The greater and more layered the artwork — and the more open and receptive the viewer — the deeper the roots and the further the journey.

Many of Mr. Serra’s sculptures threaten us. The earliest works challenge the notion of what a sculpture is, what it is made of, and where it begins and ends; or they threaten to do us bodily harm. “Delineator” (1974–75) is the first sculpture to greet viewers at MoMA. Sitting on the floor a mere 5 feet inside the first gallery, “Delineator,” a 1-inch-thick hot-rolled steel plate 10 feet wide and 26 feet long, demands that you immediately move left or right to avoid stepping on the art. After the initial shock of “Is this all there is?” wears off, the sculpture’s second act begins. Attached perpendicularly to the ceiling is a predatory steel twin to that on the floor. It hangs high over the gallery, ready to drop.

The heart-racing tension experienced in “Delineator” has very little to do with aesthetic relationships, or merit, and a lot to do with luring the unsuspecting viewer into the artwork’s trap. Yet it sets a stage, not unlike that of an amusement park fun house, in which you stay alert and step lightly. And it makes for an exciting museum trip from beginning to end.

A mishmash of Mr. Serra’s early, and least successful, works from the 1960s fills one gallery. Some of these are hanging rubber belts, objects, or planes that look like wood or dirty leather. “Untitled” (1967) is reminiscent of an Ellsworth Kelly shaped canvas, but, hanging flaccidly, it has none of Mr. Kelly’s torqued tension. The 9-foot-long rubber sculpture “Slant Step Folded” (1967) is a limp knot. “Plinths” (1967), accented with a blue neon tube, looks like giant strips of beef jerky.

“Circuit II” (1972–86), however, begins to purr. The sculpture comprises four pieces of steel, each 10 feet high by 20 feet long, that project from the corners into the center of a skylit gallery. A 3-foot-square clearing is left in the middle of the room, creating an imminent sense of doom. In another gallery, filled with delicately balanced, medium-size lead sculptures from the late ’60s, Mr. Serra, like a magician, achieves mesmerizing weightlessness.

But save your energy for the sculptures from the last 15 years. These five behemoths, which take over the Abby Aldrich Rockefeller Sculpture Garden and the Contemporary Galleries on the museum’s second floor, are Mr. Serra doing what only he can do. Just shy of architectural scale, these gracefully curving and inclining steel bands and “Torqued Ellipses” swell and flutter like ships’ sails, and their seductively bulging bodies threaten to break through the galleries’ walls and ceilings.

Their rusted, velvety orange, brown, and golden skins are sleek yet earthen, and their nature — both reptilian and womblike — is as inviting as it is menacing. Walking in and around their wobbly walls, narrow corridors, and circular clearings, which lean forward and pull you deeper, as they also appear ready to fall or to chomp down and to swallow you whole, give you sea legs; and their organic enclosures produce a specific kind of euphoric dizziness, as well as conflicting senses of burrowing, well-being, and dread.

Mr. Serra’s greatest works on view at MoMA — “Band,” “Sequence,” and “Torqued Torus Inversion” (all 2006) — were inspired by the torsions in the sculptures of Donatello, the acute angles in the pictures of the Sienese painter Sassetta, the integration of nature and control in Japanese gardens, and the industrial atmosphere of a modern shipyard. Immersing us in the active forces of all of those influences, Mr. Serra continues to create sculpture whose challenges are remarkable and inimitable.

June 3 through September 10 (53 W. 53rd St., between Fifth and Sixth avenues, 212-708-9400).