The legendary “Public Theater”  in New York City is getting a $40 million face-lift .

The  non-profit theatre based in downtown Manhattan  has a new exterior, refurbished lobby,  upgraded dressing rooms and expanded restrooms…which received the biggest cheer from the guests at  a ceremony  this week.

And those guests included Vanessa Redgrave  and Mandy Patinkin.

Mayor Michael Bloomberg was there too.

He joined other speakers  reading snippets from Shakespeare plays and enjoying the  revival cast of “Hair” serenading the crowd with a rendition of “Let the Sun Shine..”

The  project is expected to take four years.