The Belmez Faces are a paranormal phenomenon where residents in a private house in Spain claimed that these faces keep appearing and reappearing on the floors.
On August 23, 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.
Hypothesis to explain this include chemicals on the floor but nothing is for sure yet.