Visa, which for security purposes has kept its exact Tysons Corner location a closely guarded secret, has gone public with its address, although it's still a secret for most people.

"We are no longer hesitant about revealing our address. We have made a decision to disclose our address," senior vice president David A. Huemer said.

When asked to reveal the company's address however, Huchemer couldn't.

"You know, I don't know," he said. "We use a post office box for all my mailing."

The exact address of the company is 1764 Old Meadow Lane, Westage Office Complex, where the company is housed in a six-story cement and tinted glass structure known as the "Polk Building" between United Airlines' East Coast headquarters and the Olivetti building.

When Visa moved its East Coast computer operations to Tysona about 18 months ago, Huemer said, the company determined for security reasons not to publicize its presence there.

"They (Visa officials) are very much afraid of computer theft. They are wary of Stanley Riskintype thefts," Bob Torgerson, of Fairfax County's economic development authority, said.

Put when the Tysons office was elevated to Eastern headquarters for the $24 billion, world-wide firm late last year, the company's, absence from the phone directory, Huemer said, became "a gross inconvenience. Nobody could find us," he said.