This coat of arms ison the façade of the city San Peters Church in Amarante, Portugal. It is a coat of the Santa Sede of Vatican City.
"The coats of arms of the Holy See and Vatican City in the form that combines two crossed keys and a tiara used as a coat of arms of the Holy See have origins attested from the 14th century. The combination of one gold and one silver key is a somewhat later development"
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