The Bélmez faces
María Gómez Cámara said that on 23 August 1971 a human face formed on the concrete floor of her kitchen in Bélmez. More faces followed.
Wikipedia records that appearances in Bélmez were first reported on 23 August 1971. That day María Gómez Cámara claimed a human face had formed on her concrete kitchen floor. In the Pereira family's telling, María's husband, Juan Pereira, and son Miguel broke up the image with a pickaxe and laid new concrete, and a new face formed. The mayor of Bélmez was told and forbade destroying it. Workers cut out the concrete from the floor and removed it for study. The Mail & Guardian says that after Miguel covered the spot, the face was back in three days.
Atlas Obscura says María attempted to wash the face off without success.
Investigators later examined the faces. Writing in July 1993 in a Society for Psychical Research publication, Luis Ruiz-Noguez noted the presence of zinc, lead and chromium, pigments used in paint. He said two of these, lead and chromium, are the basis for suspecting that paint was used to make the faces.
"Reports of appearances in Bélmez began on 23 August 1971, when María Gómez Cámara claimed that a human face formed spontaneously on her concrete kitchen floor. María's husband, Juan Pereira and their son, Miguel, destroyed the image with a pickaxe and new concrete was laid down. However, the Pereira story goes, a new face formed on the floor. The mayor of Bélmez was informed and forbade the destruction of the new face. Instead, the floor concrete was cut out and taken for study."
- Maria Gomez and the faces of Belmez, Mail & Guardian (2004)
- Bélmez Faces, Atlas Obscura
- Bélmez Faces (investigations), Wikipedia