The echoey, dusty, gloomy galleries of the rundown Palazzo degli Studi provide one of the world’s great time-travel experiences, from grimy modern Naples back to the ancient world. Two treasure troves in particular are what bring you here. The superb Farnese Collection of Roman sculpture shows off the pieces snapped up by the enormously wealthy Roman Cardinal Alessandro Farnese, who became Pope Paul III (1543–1549) and was at the top of the Renaissance game of antiquity hunting. His remarkable treasure trove ended up in the hands of Elisabetta Farnese, duchess of Parma, who married Philip V of Spain and whose son and grandson became kings of Naples and brought the collection here in the 18th century. Among Cardinal Farnese’s great prizes was the magnificent Ercole Farnese, a huge statue of Hercules unearthed at the Baths of Caracalla in Rome. The superhero, son of Zeus, is tuckered out, leaning on his club after completing his 11th Labor. He looks a bit troubled, and who can blame him? After slaying monsters and subduing beasts, he’s just learned he has to go into the fray again, descend into Hell, and bring back Cerberus, the three-headed canine guardian. It’s a magnificent piece, powerful and wonderfully human at the same time. The colossal “Toro Farnese,” 4m (13-ft.) high, is the largest sculpture from antiquity and is carved out of a single piece of marble. Cardinal Farnese also had this prize unearthed at the Baths of Caracalla, and he had a team of Renaissance masters, Michelangelo among them, restore it, piecing together bits and pieces here and there. The intricate and delicate work depicts one of mythology’s greatest acts of satisfying revenge, when the twin brothers Amphion and Zethus tie Dirce—who had imprisoned and mistreated their mother, Antiope—to the horns of a bull that will drag her to her death.

On the mezzanine and upper floors are mosaics, frescoes, and bronzes excavated from Pompeii and Herculaneum. Those sights, of course, are remarkable, but seeing these objects from villas and shops hauntingly brings the ruined cities to life as they show off the residents’ tastes and preoccupations. Some, such as baking equipment and signage, are quite mundane, touchingly so; many, such as the bronze statues of the Dancing Faun (on the mezzanine), the Drunken Faun (top floor), and five life-size female bronzes known as Dancers (top floor) show off sophisticated artistry. Most of the mosaics, on the mezzanine, are from the House of Faun, one of the largest residences in Pompeii. The million-plus-piece floor mosaic, “Alexander Fighting the Persians,” depicts the handsome, wavy-haired king of Macedonia astride Bucephalos, the most famous steed in antiquity, sweeping into battle with King Darius III of Persia, who’s looking a bit concerned in his chariot. The Gabinetto Segretto (Secret Room; also on the mezzanine) displays some of the erotica that was commonplace in Pompeii. Some works are from brothels, among them frescoes that show acts lively yet predictable and some bestial (literally, as in Pan copulating with a goat) and others include phallus-shaped oil lamps and huge phalluses placed at doorways to suggest fertility and good fortune. We might titter at the bulges under togas and a fresco from Herculaneum’s House of Papyri showing a gent weighing his huge member, but they weren’t necessarily intended to be pornography and rather suggest the libertine attitudes of the time.