A mid-rise office building in downtown Pasadena, California, that’s been subject to (not totally implausible) conspiracy theories over the years was sold earlier this month in a $72 million transaction to Atlas Capital Group as reported by The Real Deal.

Completed in 1974, the building’s most notable features include its travertine-clad facade and a near-complete absence of windows save for the ground level. Yes, no windows. It was designed by the namesake firm of marquee modernist architect Edward Durell Stone, an Arkansas-born 20th-century powerhouse whose long list of notable projects includes the U.S. Embassy in New Delhi, India; PepsiCo headquarters in Purchase, New York; the General Motors Building in Manhattan; Westgate Tower in Austin, Texas, and both the John F. Kennedy Center for Performing Arts in and the National Geographic Society building in Washington, D.C., Early in his career, Stone also had roles in the design of the Museum of Modern Art and Radio City Music Hall.

The 360,000-square-foot Pasadena building, long shrouded in mystery because of that signature design feature, isn’t one of Stone’s better-known works, and was approved for a substantial redesign early last year by city planners with the blessing of Pasadena’s top historic preservation brass. Stone himself, who died four years after the building was completed, reportedly wasn’t directly involved in the design of the building, which was ultimately “heavily modified” to be more imposing by Bank of America officials, per the Pasadena Star-News.

“Pasadena Heritage agrees with the conclusion that the building does not rise to standard of significance for landmark or National Register (of Historic Places) status, though it remains, certainly, a building of interest that has held its place on that corner for decades now—with various opinions about it having been expressed over the years,” Susan Mossman, executive director of Pasadena Heritage, explained to the Star-News last year.

Occupied by the Bank of America from its completion up until last year, the monolithic slab of a structure (locally referred to as the Bank of America building) isn’t completely without historical significance. Per the Star-News, it served as a processing center for the BankAmeriCard, which was the first credit card—a direct predecessor of the Visa card—that permitted cardholders to carry a balance.

Prior to its sale to Atlas Capital Group, the old Bank of America building was owned by Woodbridge Capital Partners, the same real estate investment firm that had sought permission from the city to dramatically revamp the structure last year. While it’s unclear what Atlas Capital Group’s exact plans for the building are, it will presumably include windows.

“Creating some window openings should be able to be done attractively and appropriately to make it a usable building. Given its size and location, it is certainly important that it have a new, productive use,” wrote Mossman of Pasadena Heritage last year.”This is not a demolition but a modification which should be able to be successfully accomplished.”