The Basilica della Madonna dell'Umiltà is the largest Renaissance church in Pistoia, built in the 16th century to house a venerated image of the Virgin. The exterior is plain brick, which makes the interior dome — added by Giorgio Vasari in the 1560s — all the more surprising: a vast octagonal cupola frescoed with scenes of the Virgin's glorification, rising unexpectedly over a relatively modest nave.
The church is still active and the interior is regularly open. The dome frescoes were completed after Vasari's death and have the slightly overcrowded quality typical of late Mannerist decoration, but the sheer scale is impressive. The church sits a few blocks south of the Piazza del Duomo and is easy to combine with a walk to the Ospedale del Ceppo.