Ted Hustead was kind of a nut for self-promotion. When he bought a drugstore in tiny Wall, South Dakota, in 1931, he figured he could attract customers through advertising.

Maybe he overcompensated a little. There are now 500 miles of Wall Drug billboards on Interstate 90, stretching all the way to Minnesota at an annual cost of $400,000, plus signs at the North and South Poles, the Paris Metro, and the Taj Mahal. The photo above was taken somewhere in Africa in the 1950s.

The signs may be eyesores, but they’re scaring off the competition — the little pharmacy is still the only one within 500 square miles.