The name misleads: the "conservatorio" of San Carlo is not a music school but one of Pienza's historic institutions, founded in the seventeenth century and expanded over the generations that followed. The complex began life as a monastery of Augustinian nuns, established in 1634, and in 1787 it became a conservatorio femminile — one of the Tuscan institutes of the period devoted to the education of girls.
The institution still exists, today as a foundation — the Fondazione Conservatorio San Carlo Borromeo di Pienza — which owns several buildings in town.
What to see
The most valuable piece is in the church: on the high altar hangs a canvas painted between 1620 and 1625 by Francesco Rustici, known as il Rustichino, a Sienese painter who died young in 1626 and is remembered above all for his candlelit scenes. Here he depicts the Madonna and Child with Saints Charles Borromeo, Francis, Clare, Catherine of Siena and John the Baptist.
The choice of saints repays a closer look: Charles Borromeo had been canonized in 1610, barely a decade earlier. When Rustichino painted him, the church's titular saint was brand new — evidence of a devotion that caught on in Pienza almost in real time.
Visiting
The complex stands in the historic centre of Pienza, a few minutes on foot from piazza Pio II. It is not a museum but the seat of a working institution: the space to look for is the church, with Rustichino's altarpiece over the high altar. The visit is short and slots easily into a walk around the town centre.
Our editors' tip
Treat the conservatorio as your way into "minor" Pienza: after the cathedral and Palazzo Piccolomini, it is places like this — a seventeenth-century convent turned girls' institute turned foundation — that tell you how the town actually lived in the four centuries after Pius II's grand project. And in front of the altarpiece, find Catherine of Siena among the figures: in a town built by a Sienese pope, her presence beside Charles Borromeo is anything but accidental.