It's only lit once every year.
However, the beacon atop Mount Diablo is a fixture and, supporters say, an important landmark for the community.
Now, the so-called Eye of Diablo is in need of repair and officials at Save Mount Diablo are asking for the public's help.
A by Gov. Jerry Brown gave the non-profit organization authorization to enter into an agreement with the state parks department to restore the beacon.
Save Mount Diablo Executive Director Ron Brown said they are looking for volunteers as well as donors.
The project will probably cost between $20,000 and $40,000, depending on how much work needs to be done and how many volunteers with expertise sign up.
The beacon is lit every Dec. 7 to honor the veterans who were stationed at Pearl Harbor, Hawaii, when it was attacked by Japanese war planes in 1941.
Brown said the beacon barely works now and needs a complete overhaul. The group won't know how extensive the repairs are until they take the beacon apart and look at its wiring, structural support and other things.
Save Mount Diablo hopes to have the beacon restored by Dec. 7 for this year's ceremony.
Brown admits that's an optimistic goal. Anyone who would like to donate or volunteer can go to the group's website or call 925-947-3535.
The beacon was installed in 1928 as part of a system of lights across the United States to guide planes during nighttime flights. Each beacon was 50 to 100 miles apart.
The light atop Mount Diablo switched on every evening until 1941 when it was shut off after the Japanese attack on Pearl Harbor.
When the war ended in 1945, there was radar and other technology that made the beacon obsolete.
In 1964, survivors of the Pearl Harbor attack started the annual Dec. 7 ceremony.
"Basically, the beacon is primarily used for one day a year," said Brown.
Seven years ago, discussions began about restoring the beacon. Save Mount Diablo is now in charge of that task.
Brown said it's important to keep the beacon operating because of the ceremony it's used for.
"The beacon represents freedom and honors the citizens of our country who fought to keep it for us," he said.