The complete story behind Apple's futuristic new campus, 'Apple Park'

Apple employees will begin moving into a new campus in Cupertino, California this month. 

The new Apple headquarters, named Apple Park, is a single ring, about a mile in diameter, set in a large campus that will be covered in plants and trees.

Late Apple CEO Steve Jobs once said that the new campus was "a shot at building the best office building in the world."

It will house 13,000 employees on over 2.8 million square feet of office space. Apple employees will enjoy fruit trees, a massive fitness center, and a workspace that's been carefully overseen by Jony Ive, Apple's chief design officer. 

The Apple HQ has been compared to a UFO and the Pentagon - and after about $5 billion in costs, according to Apple CEO Tim Cook, it's ready to open. 

Here's a look at Apple Park over the past five years, and what still needs to be done: