An 11-day tour, a huge entourage and traffic at a standstill: another ageing rock star hits LA

340-tonne block of granite completes epic journey to become city's latest landmark

It is, quite literally, a rock star. And like many who suddenly achieve this lofty status, it has taken up residence a stone's throw from Hollywood.

A block of granite weighing 340 tonnes, and measuring roughly the size of a two-storey house, arrived in central Los Angeles at the weekend, completing an extraordinary journey into the annals of contemporary art.

The boulder, which originated in a quarry roughly 100 miles inland, is to be placed above a long, narrow trench. Once set in place later this year, it will become Levitated Mass, an installation by the artist Michael Heizer, and will grace the grounds of the Los Angeles County Museum of Art (LACMA). Its creator hopes it will give visitors the impression that the boulder is floating.

Regardless of whether this trompe l'oeil works, the rock's status as LA's latest cultural landmark has surely been already assured by the public excitement which has accompanied its $10m (£6.3m) journey to its final destination.

After being wrapped in white plastic and loaded on to a 176-wheel, centipede-like transporter at a quarry in Riverside County, it spent 11 days and nights crawling across 22 of Southern California's cities. Crowds ran alongside, shooting video and creating a television spectacle.

When it arrived in Long Beach, the city threw a "block party" that attracted thousands of revellers. As it trundled through Ontario, in east Los Angeles, Ramone Vasquez dropped to one knee, in front of waiting TV crews, and proposed to his girlfriend, Maria.

"That rock won't fit on your finger," he said, producing an engagement ring. "But maybe this one will."

At various stages in its journey, the boulder flirted with disaster. In Chino, it squeezed under a bridge with six inches to spare. In West LA, it passed through a series of streets so narrow that the transporter was just two inches from the kerb.

On the final few miles to LACMA, workers were forced to remove two palm trees (they must now be replaced) and tow away several parked cars.

The rock finally arrived at 4.25am on Saturday. Despite the ungodly hour, a thousand-strong crowd stayed up to witness the end of its journey.

Over the next month, the transporter will be dismantled and the boulder moved on to metal rails above its 456-foot long trench.

"As far as I'm concerned, it's like the pyramids," said Sandy Martin, an onlooker. "We will never see this again in our lifetimes. I cried when I saw it."

To those who called the whole thing a publicity stunt, the LA County superviser Zev Yaroslavsky told the LA Times: "This rock has taken the region by storm. People can love it or hate it, but they are all consumed by it.

"It has the whole town talking, which is what art is supposed to do."