Alan Gerry (third left) opened the site on Monday

The $63m (�33.8m) venue, the Bethel Woods Center for the Arts, will feature a 4,500-seat amphitheatre and space for another 12,000 on the lawn.

It is the first permanent structure on the festival site.

The decision to build on the site has been met with criticism by the Woodstock Preservation Alliance.

"There are so many people upset about this move. We still support the arts centre and what it may do for Sullivan County," the Alliance's Brad Littleproud said.

"However, the Gerry Foundation has been given carte blanche to interpret and desecrate an icon to a generation."

The 1969 festival, touted as a celebration of "peace, love and music", featured some of the biggest names in Sixties rock, including the Jimi Hendrix, the Grateful Dead, The Who and The Band.

'Community project'

An estimated 400,000 people saw the concert, which was celebrated with a three-hour documentary film.

Other festivals were held on the site in 1994 and in 1999.

Construction crew have spent the last month moving earth from the site, on a hillside overlooking where the festival's main stage had been. An opening ceremony was held on Monday.

Jimi Hendrix was one of the acts who played the 1969 festival

Yasgur's old farm is now owned by a non-profit organisation, the Gerry Foundation, which is financed by Alan Gerry, a millionaire businessman who bought the 37-acre (14.8 hectare) site in 1997.

He later bought another 1,300 acres (520 hectares) surrounding the site.

"This is truly a community project," Mr Gerry said on Monday at the opening ceremony.