Towerheath - Light Manufacturing and Design

They don't make 'em like they used to. The Centennial Light, located in a firehouse in Livermore, CA, has been running for 106 years with only short interruptions, making it the longest-burning light bulb in the world. The four-watt bulb, which is currently used as a night light above the fire trucks, was turned off only once, when it was moved from one fire station to another.

Source – 2007 Guinness Book of Records.

For more information have a look at the website dedicated to the Centennial Light