The Museo dell'Opera del Duomo - Florence

The Opera del Duomo, also known as the "OPA", is the the Cathedral Workshop or "works commission" and was founded by the Republic of Florence in 1296 to oversee the construction of the new Cathedral and its bell tower.
In 1436, the Cathedral was finally finished with the completion of Brunelleschi's dome and its consecration.
Since then, the main task for the Opera del Duomo has been to conserve these monuments - including the Baptistery of San Giovanni. In 1891, the Museum was founded to house the works of art which, through the course of the centuries, had been removed from the Duomo and the Baptistery.
The museum serves as a refuge from pollution for many of the outside sculptures of the cathedral.