This crest is displayed to the right of the front door of the church designated as the Church of the Senate and the People of Rome, Santa Maria in Ara Coeli. It is on the Capitoline Hill next to the buildings of the Roman City Government that are around the Campidoglio, the Renaissance piazza designed by Michelangelo.
This is the brick facade of the church, seen between the white marble of the Monument to Victor Emmanuel II and one of the buildings of Michelangelo's Piazza. (For more about the church see the post below.)
SPQR are the first letters of the words in the Latin phrase Senatus Populusque Romanus, "The Senate and the People of Rome." It originally referred to the government of the ancient Roman Republic, and used as an official signature of the government, appearing on coins, civic inscriptions, and on the standards of the Roman legions. SPQR is the motto of the city of Rome and appears in the city's coat of arms, as well as on many of the city's civic buildings, public fountains, manhole covers, billboards and even some churches.