The city of Florence — the birthplace of the Renaissance — attracts millions of tourists annually to see art masterpieces in famous museums (for instance, Michelangelo’s David and Botticelli’s Birth of Venus), rub the snout of Il Porcellino in the central market (hands off the original marble in the Uffizi Gallery), and visit religious sites, including the Duomo, the third-largest church in the world (after St. Peter’s in Rome and St. Paul’s in London).

The Duomo. Architect Filippo Brunelleschi’s massive cupola — all four million bricks of it — has dominated Florence’s skyline since 1434. It sits atop an ornate wedding cake of a cathedral, the Basilica di Santa Maria del Fiore, aka the Duomo, which is frosted in white, pink, and green marble. Tourists go gaga (and take selfies).

Then, many of them make the incorrect assumption that the inside must be equally stunning.

So they form a line that can snake along the entire 500-foot length of the building and wait an hour (or more) for a chance to see ... very little. There's a pretty mosaic floor, a clock, and, if you crane your neck and squint, frescoes painted inside the dome.

You can climb the dome for 360-degree views, but that requires snagging a reservation and ascending 463 steps, which might actually be less challenging. The genius move for cathedral connoisseurs? Pop into the recently renovated Museo dell’Opera del Duomo, home to masterpieces made for the complex, including Donatello’s haunting wooden sculpture of Mary Magdalene and Lorenzo Ghiberti’s gilded baptistery doors. Plus, its elevator-accessible terrace offers dome close-ups.

Piazza del Duomo. Admission: Free to the cathedral floor; about $20 for access to the dome, baptistry, bell tower, crypt, and museum. Hours: 10 a.m.to 4:30 p.m. for the cathedral; various times for other attractions. Information: operaduomo.firenze.it/en.

Fra Angelico's "Annunciation" in the Museo di San Marco.
Museo di San Marco
Fra Angelico's "Annunciation" in the Museo di San Marco.

Museo di San Marco. Inside this calming cloister of a monastery a few blocks from the Duomo, you’re immediately introduced to the star of the show: Fra Angelico. His fresco of Saint Dominic gripping the crucifix demonstrates why the “Angelic Friar” was one of the Renaissance’s favorite artists.

Among the ground-floor galleries, you'll find not just Fra Angelico's most glam works (such as Tabernacle of the Linen-drapers, featuring Mary in a luminous blue mantle), but also Lamentation with Saints, a rare painting by a nun, Sister Plautilla Nelli. Waiting at the top of the stairs is Fra Angelico's Annunciation, which you'll recognize from art history textbooks. Only in person will you see the angel's wings shimmer.

This floor is lined with former monks' cells, most decorated with a fresco Fra Angelico painted himself. These works were designed for spiritual meditation, which explains the minimalist style and muted colors.

Museo di San Marco: Piazza San Marco 3. Admission: Adults, $12; children (6-17), $7.50. Hours: Weekdays, 8:15 a.m. to 1:15 p.m.; Saturdays, 8:15 to 4:15. Information: polomusealetoscana.beniculturali.it (in Italian) and various sites.