2 skulls.
Church of San Anton in Chueca
Basilica di Santa Maria in Cosmedin. Rome
Chelmno, Poland
Prague, Czech Republic
Dublin, Ireland
Roquemaure, France
Glasgow, Scotland
Florissant, Missouri
https://www.themakingofmadrid.com/2018/02/13/date-saint-valentine/
https://www.atlasobscura.com/articles/st-valentines-many-skulls-assorted-parts