Infinite Loop is a street encircling the six main buildings of Apple's headquarters in Cupertino, California. Each building has a number which corresponds to its single-digit address on the Loop, and so Apple's official mailing address is "1 Infinite Loop". The numbers increment in the clockwise direction. Employees often refer to the buildings as IL1 through IL6. The loop connects to Mariani Avenue, which was the former street address of Apple HQ; early printed material contains the address "20525 Mariani Avenue". This is right next to Lawson Middle School.
Infinite Loop is at the southeast corner of De Anza Boulevard and Interstate 280. The main office, 1 Infinite Loop, directly faces De Anza Boulevard. There are other buildings on Apple's campus which are in the proximity of, but not on Infinite Loop. Apple has purchased a nearby parcel of land on which to build a second campus.
The name was inspired by the programming concept of the infinite loop.
Infinite Loop is actually a private U-shaped crescent, which joins up with the public street Mariani Avenue to form a loop.