The masterpieces here are considered Rome’s most valuable (considering how the Vatican Museums are not part of Rome). This is also the oldest public museum in the world, with lots to see, so try to schedule adequate time.
First stop is the courtyard of the Palazzo dei Conservatori (the building on the right of the piazza designed by Michelangelo, if you enter via the ramp from Piazza Venezia), a space scattered with gargantuan stone body parts. They’re the remnants of a massive 12m (39-ft.) statue of the emperor Constantine, including his colossal head, hand, and foot, from the Basilica of Maxentius and Constantine in the Roman Forum. It’s near impossible to resist snapping a selfie next to the giant foot.
On the palazzo’s ground floor, the unmissable works are in the first series of rooms. These include “Lo Spinario” (Room III), a lifelike bronze of a young boy digging a splinter out of his foot that was widely copied during the Renaissance; and the “Lupa Capitolina” (Room IV), a bronze statue from 500 b.c. of the famous she-wolf that suckled Romulus and Remus, the mythical founders of Rome. The twins were not on the original Etruscan statue; they were added in the 15th century. Room V has Bernini’s famously pained portrait of “Medusa,” even more compelling when you see its writhing serpent hairdo in person.
Before heading upstairs, go toward the new wing at the rear, bathed in natural light thanks to a enormous modern skylight, which houses the original equestrian statue of Marcus Aurelius ★★★, dating to around a.d. 180—the piazza outside, where it stood from 1538, now has a copy. There’s a giant bronze head from a bronze statue of Constantine (ca. a.d. 337) and the foundations of the original Temple of Jupiter that stood on the Capitoline Hill since its inauguration in 509 b.c.
The second floor is known for its picture gallery ★, which is strong on baroque oil paintings, with masterpieces including Caravaggio’s “John the Baptist” and “The Fortune Teller” (1595) and Guido Reni’s “St. Sebastian” (1615).
An underground tunnel takes you under the piazza to the other part of the Capitoline Museums, the Palazzo Nuovo, via the Tabularium ★. This was built in 78 b.c. to house Ancient Rome’s city records, and was later used as a salt mine and then as a prison. The atmospheric stone gallery was opened to the public in the late 1990s to exhibit inscriptions, and also to provide access to one of the best balcony views ★★★ in Rome: along the length of the Forum toward the Palatine Hill.
Much of the Palazzo Nuovo is dedicated to statues that were excavated from the forums below and brought in from outlying areas like Hadrian’s Villa in Tivoli. If you’re running short on time at this point, head straight for the 1st-century “Capitoline Venus” ★★, in Room III, admire a modest girl covering up after a bath and a chronologically arranged row of busts of Roman emperors and their families (Room IV). Another favorite is the beyond handsome “Dying Gaul,” a Roman copy of a lost ancient Greek work. Lord Byron considered the statue so lifelike and moving, he included mention of it in his poem "Childe Harold’s Pilgrimage."