Since the 1930’s, there has been a group of trees growing in Germany that outline the shape of a swastika. The symbol, which is most widely known as an icon of hate and Nazi propaganda from Hitler’s reign, can only be seen during a few weeks a year and from a certain altitude; for those reasons, they went unseen for decades.

According to the New York Daily News, in 1992, landscaper Günter Reschke had his intern, Ökoland Dederow, scouring aerial photos for irrigation lines. It’s normally a long, tedious job saved for lowly interns, but Dederow was thankful later that he’d been given the task; as he was sifting through them, he discovered a group of larches standing among hundreds of pine trees. The larches, unlike the evergreens, had changed to a gold color in the fall, leaving a gold swastika in the middle of a field of green. Because commercial flights would already be too high up by the time they passed over the area in Brandenburg and private planes were banned, no one ever saw the symbol from the air, where it was clearly meant to be viewed.

The origin of the swastika has been hotly debated over the years; one man claimed he planted the trees for the Nazi forestry service as a child, earning a few cents for each seed he put in the ground. Others say it was put there to honor Hitler’s birthday. Whatever the reason for its existence, it drew quite a bit of backlash from those who wanted it gone. Not only was it a painful reminder of the country’s history, it was feared by German leaders that the area might become a haven for neo-Nazi groups.

In 1995, efforts were made to destroy the symbol; 40 trees were cut down, but five years later, aerial photos showed that the swastika was still there. Workers had chosen the wrong trees to take out, and hadn’t destroyed the original image. In 2000, ownership of the land went into dispute and again workers were brought in to clear out the swastika, but they were only allowed to take so many trees due to legal issues. After careful planning, they finally managed to take out the symbol. However, it’s still a sore spot for those who live in the area, and many still want to know where it really came from.

Adding to the mystery are sightings of other swastika formations in other German towns; at least four since the 1970s, and no one will claim responsibility.