Image caption Heizer first conceived the idea for Levitated Mass in 1969

A new work of art featuring a rock weighing 340 tons (308,443 kg) has gone on display at the Los Angeles County Museum of Art (LACMA) in California.

Artist Michael Heizer unveiled Levitated Mass to more than 1,000 people on Sunday.

Positioned above a walkway, the outdoor sculpture is designed to look as if it is floating in mid air.

The boulder is intended to stay there permanently after being hauled 105 miles (169 km) from a rock quarry.

Heizer, 67, made a rare public appearance at LACMA for the ribbon-cutting ceremony and led the first procession through the 465 foot (142 metre) trench beneath the rock.

The artist is best known for Double Negative, a land sculpture cut into the desert in southern Nevada.

Image caption The boulder took two weeks to transport on a specially built trailer

Heizer first had the idea for Levitated Mass in 1969. But he did not locate the perfect rock until around seven years ago in Riverside County, California.

It then took dozens of people and a specially built trailer to haul it through 22 cities at a speed of around 5 mph.

The museum is offering free admission to anyone living in the areas the rock passed through on its two-week trip, to thank them for tolerating road closures and other delays.

According to the venue, the work combines ancient traditions of creating artworks from megalithic stone with modern forms of abstract geometries and cutting-edge feats of engineering.