Apple's New Campus in Cupertino, California,USA

Construction continues at  Apple's new California campus in Cupertino with one of the most difficult aspect of the project underway - the installing of the world's largest piece of curved glass.

More than 3,000 curved panes will be used in the end around both sides of the circular four-story building, which is over a mile around.

The world's largest piece of curved glass is currently being put in place at Apple's new campus in Cupertino, California,USA

More than 3,000 curved panes will be used in the end, measuring over six kilometers around the outside of the building

The formidable structure of concrete, chrome and glass at the 175-acre Campus 2 site, which was first proposed by Steve Jobs in 2011, is due to open at the end of this year