LOS ANGELES: The 340-ton granite rock that became a star during its slow sojourn across California roads in March took up residence at the Los Angeles County Museum of Art on Sunday at an unveiling that included an appearance by the reclusive artist who conceived the project.

"Levitated Mass," the well-travelled boulder at the centre of artist Michael Heizer's new art work, drew the admiration of museum director Michael Govan, museum board co-chair Terry Semel, Mayor Antonio Villaraigosa and other local dignitaries at a ribbon-cutting.

"Art is made to memorialize time," Heizer, making a surprise appearance, told Reuters. "A culture is known by its art, not by its science."

After opening remarks, the committee led hundreds of art lovers through the 456-foot-long (140 meters) groove that runs beneath the 21-foot-high (6.4 meters) boulder in the museum's north lawn.

"It does make the impossible possible," Govan told the crowd. "As Michael said to me once, when do you ever get to see the bottom of sculpture?"

The stone made its 106-mile (170 km) journey over 11 days in March, inching nightly on a massive heavy-duty trailer along California highways at an average speed of 7 miles per hour (11 kph). It rested in the middle of the road by day, forcing the closure of some traffic routes.

The sojourn sparked celebrations in neighbourhoods along its route and made headlines around the world.

"Los Angeles is an automobile culture," Heizer said. "What you saw was just the biggest automobile in town going down that road."

PROJECT DATES TO 1968

Heizer, 67, has lived in a remote Nevada desert for the past 40 years, carving "City," a monumental landscape sculpture to rival Mount Rushmore, out of the earth.

He conceived of "Levitated Mass" in 1968 when he found a similarly shaped but smaller (120-ton) boulder in Nevada, which he attempted to place over a slot dug in a dry lake bed. The effort, which broke the boom on a crane, ended in failure.

After years of searching and producing subsequent landscape installations such as "Double Negative" (1969-1970), two enormous trenches each 50 feet (15 meters) deep and 30 feet (60 feet) wide, with a combined span of 1,500 feet (457 meters), on the eastern edge of Mormon Mesa, Nevada, Heizer found the perfect boulder for a second go at "Levitated Mass."

"We knew it was going to attract attention," Heizer said, addressing the media attention lavished on last winter's move, as well the well-attended Sunday debut. "That's not really the art, as far as I'm concerned."

The journey and installation of the new artwork cost about $10 million, causing some to question such profligacy during lean economic times.

But Govan insisted that the funds, which were raised through private donations, created jobs for those who moved the boulder, and predicted "Levitated Mass" would draw tourist dollars into the city, although there is no charge for viewing the sculpture.

"It is a monument to our own time and our own place and our own aspirations as people," said Govan. "Perhaps it will be here millennia forward, to communicate those feelings to future civilizations."