Portland, Maine, has a secret admirer. Each Valentine's Day, flyers and banners with pink and red hearts appear in random spots around the city. According to Bangor Daily News, no one has claimed responsibility for the anonymous valentines in 41 years.

The first evidence of the so-called "Valentine Phantom" (who is sometimes referred to as the "Valentine Bandit") surfaced in Portland in 1976. Paper hearts were found plastering the streets on the holiday, with no clues indicating where they came from. The mystery only grew as the hearts returned every year on February 14. There's no pattern dictating where the hearts are placed; they've been found on everything from snowbanks to landmarks. Massive banners have also been hung up in prominent places. In the past decade, giant hearts have emblazoned the Portland Public Library and the ruins of Fort Gorges in Casco Bay.

In 2017, Bangor Daily News landed an exclusive interview with the Valentine Phantom. The mysterious force is actually a crew of Valentine's Day-lovers with connections to various sites and buildings around the city. The perpetrators declined to share their identities, telling the outlet, “Most people are dying to be in the paper. This is the opposite. This is not ego-driven.”

The Phantom has done more than spread good feelings to fellow Portlanders on Valentine's Day; they've sparked a nationwide trend. Similar anonymous heart flyers have appeared in Montpelier, Vermont, and Boulder, Colorado.

[h/t Bangor Daily News]