437 25th Street
The Fire Alarm Police Telegraph system was the cutting edge of public safety a century and a half ago. It was a wired system that connected battery-powered alarm boxes to transmit alarms instantly across a city. San Francisco had such a system in 1865, described in a history on the S.F. City Museum site. The 1906 earthquake led to complete upgrades in this system. San Francisco dedicated its new Central Fire Alarm Station in 1915, but Oakland was ahead of that city, having finished its fire alarm police telegraph system in 1911. A main building at 13th and Oak Streets was connected by underground cables to police stations and call boxes and fire stations across the city. “With its isolation, fire-proof construction and underground system of cables,” the Tribune reported, “the entire city might burn or be shaken to pieces by earthquake and the operation of the system would not be disturbed in the least.”
Presumably this access cover dates from that time and belonged to that system.
Oakland Underfoot 
29 April 2021 at 9:51 am
Over on Facebook, Robert Blaze commented, “Yes that was a part of the City system. The vault underneath is a brick octagon manhole. I was the last City Cable splicer and was in that hole a number of times. If you would like more info on the Police and Fire boxes and system, visit http://www.myoldfirebox.com“