Adding fuel to rumours that Apple is working on designs for a car, the giant tech company is said to be looking at using a former navy base that’s been converted into a testing ground for self-driving cars and other cutting-edge vehicles.

Apple, which is best known for making iPhones and Mac computers, hasn’t said what kind of testing it hoped to conduct at the GoMentum Station automotive testing facility, which used to be a naval station in the San Francisco Bay Area city of Concord.

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“We don’t know. They haven’t said what they want to test. It could be an iPhone,” joked Jack Hall, program manager for connected vehicles and autonomous vehicles at GoMentum Station, which is operated by the Contra Costa Transportation Authority.

The agency is promoting a portion of the former Concord Naval Weapons Station as an ideal testing facility for carmakers and tech companies working on automotive technology.

“It’s got all the infrastructure of a city,” Hall said of the facility. “There are buildings, streets and intersections, but no people.”

The 2,023 hectare site has 32km of paved roads, including overpasses, tunnels and railroad crossings, according to the agency’s website, which calls it “the largest secure test facility in the world.” Another 3,075 hectares of the former navy base is now used as a shipping terminal by the US Army.

GoMentum Station already has an agreement with Honda, which plans to test automated vehicle systems there. Hall said his agency hopes to partner with other companies for testing self-driving cars and “connected vehicles” – cars that use the internet and local networks to exchange a variety of information with other devices and vehicles.

Apple has “shown interest” in the facility but has not reached any agreement for testing there, Hall said. Company representatives have not actually visited yet, he said. An Apple spokesman declined to comment Friday.

A number of automakers and tech companies, including Google, are working on new designs for autonomous and electric-powered vehicles.

In February, The Wall Street Journal cited unnamed sources who said Apple is working on designs for an electric vehicle to be sold under the Apple brand. Analysts say Apple has the financial wherewithal and ambition to pursue such a project, although some believe it’s more likely interested in developing software for use in cars made by other companies.