Escher produced '8 heads' in 1922 - a hint of things to come. You can immediately see 4 different heads but the others are not apparent until the picture is turned upside-down
Also in this year, he took a boat trip to Spain and went to the Alhambra where, as we have seen he copied many of the tiling patterns.
'8 Heads' by M. C. Escher (1922) By permission Cordon Art - see site information.