Add one more reason to clean out your closets. A forgotten painting by 16th-century Dutch master Otto van Veen has turned up in a museum closet in Des Moines, Iowa, after being hidden for almost a century.

Ahead of President’s Day weekend in 2016, director of Hoyt Sherman Place arts complex Robert Warren was looking for Civil War-era flags in a little-used closet under the auditorium’s balcony. Instead, he found a $4 million Old Master painting stuck between a table and the rear wall.

Depicting the Greek gods Apollo and Venus and a cherub (perhaps Venus’s son Cupid), the work was later identified as Van Veen’s Apollo and Venus (circa 1595–1600).

“I didn’t think it was anything of value,” Warren said about the damaged painting in an interview with WTKR, “I wasn’t sure why it would’ve been in that closet.”

It was a sticker on the back of the canvas that prompted Warren to investigate further. What looked like an auction house tag was actually a label from the Metropolitan Museum of Art in New York, where it had been on view.

After doing a little digging, he found that the artwork was loaned to the Met by the collector Nason Collins, who later moved to Des Moines and took the work with him. In 1923, Collins’s granddaughter donated the painting to the Des Moines Women’s Club, which was located at Hoyt Sherman.

Warren speculated that the work was hidden away either because of the damage it had sustained or because of the work’s eroticism. “There were no other nudes in any other pairings in the collection,” he told WTKR. “It’s a very sensual painting.”

After a year of extensive restoration and reframing, the artwork is finally back in Des Moines, where it was unveiled in a private ceremony last month. Warren said the work will not be sold and that Hoyt Sherman Place plans to put Van Veen’s masterpiece on permanent display in its gallery. But first, the museum must upgrade its security infrastructure. It turns out that owning a multi-million dollar painting comes with its own challenges.

Warren did not immediately respond to artnet News’s request for comment.