Twelve ghostly figures watch over San Francisco’s financial district from a rooftop perch 23 stories up, spooking those who spot them as they have for more than 20 years.

Artist Muriel Castanis, known specifically for her eerie draped figures, created the 12-foot high sculptures for the Philip Johnson-designed building in 1982, looking out from the four sided rooftop, three to a side. Since they were revealed they have been interpreted as everything from grim reapers to angels, but the artist described them as “corporate goddesses.”

The official project documentation takes the high road, describing them thus: “They are empty, toga-draped forms from which the figures have been removed, rendering the sculptures as abstracted reinterpretations of the neoclassical masterworks of Lorado Taft and Augustus Saint Gaudens.”

Another set of Castanis’ ghostly figures known as the “Flatbush Floogies” can be seen on the walls of the Flatbush Avenue-Brooklyn subway station in New York.