But what the eternal city lacks in true culinary cosmopolitanism, it makes up for in variety of a different kind. Until 1871 Italy was a free-for-all of truculent principalities, kingdoms, and client states. To this day, the country remains a fractious potpourri of 20 regions that vary widely in culture, customs — and, above all, food. As the capital of such a dizzying cornucopia of regional flavors, dishes, and styles, Rome’s cup runneth over with restaurants specializing in these distinctive cuisines. So when Romans want to take a walk on the gustatory wild side, they don’t go out for Ethiopian or Thai — but Sicilian, Sardinian, or Ligurian, among others.

For visitors to Rome with venturesome palates, that means a gastronomic tour of Italy doesn’t have to entail a slog to the four corners of the peninsula. You can sample it all without ever setting foot outside the city limits. Best of all, these restaurants open a window onto the heart and soul of the region whose typical fare they dish out.

On a recent trip I decided to visit (or revisit) the cream of the regional restaurants in town. Some are haunts from the decade I lived in Rome; others were recommended by Italian and expatriate friends who, along with the city’s myriad enchantments, lure me back year after year.

Geography is destiny, they say, and none of Italy’s regions better illustrates that adage than Sicily. A stepping stone at the crossroads of Europe, the Middle East, and North Africa, the island has been on the sharp end of countless foreign powers’ imperial ambitions, from the Greeks, to the Spanish, to the Arabs. Those waves of invasion have made Sicily’s cuisine as rich as the hyper-fertile volcanic soil that blankets its hilly terrain and yields some of the most flavorful produce on earth.

For a sampling of that lava-fed richness, I made my way to Capricci Siciliani. Housed in a 12th-century palazzo once owned by the influential Orsini family, the restaurant affords a chance to feast on classic Sicilian fare against a backdrop of Romanesque elegance. Warmly lighted groin vaults soar above walls festooned with Sicilian ceramics, armor-clad puppets, and rusted coats of arms. The effect is enchanting; the food superb.

True standouts are the insalata di polipo, a succulent, citrusy antipasto of sliced octopus and caponata, a relish of tomatoes, eggplants, olives, capers, pine nuts, garlic, and raisins that has a distinctly Arab-tinged sweet-sour finish. Fusilli with almond pesto is also spectacular. Another favorite, grilled swordfish alla Ghiotta, topped with a complexly spiced sauce of cherry tomatoes, olives, capers, and raisins, is as moist a slice of swordfish as you’ll ever not have to chew. Save enough room for dessert: the cassata, a ricotta-laced cake in a shell of marzipan, is a delightful ménage of spongy, creamy, and firm.

On the opposite end of the country, both geographically and temperamentally, lies Liguria, a thin boomerang-shaped strip of a region joining the slender trunk of Italy to the French Riviera. Luckily, Taverna Giulia, bulwark of Ligurian cuisine in Rome, is a mere stone’s throw from Capricci Siciliani, saving you a 14-hour overland traverse.

Ligurians were accomplished seamen, operating a merchant fleet that rivaled the Venetians’. Long months at sea noshing on bland provisions whetted Ligurians’ appetites for flavors redolent of forest and field. Hence the special place occupied by aromatic herbs in Ligurian gastronomy.

“Basil,” my genial waiter informs me, “was a sacred plant to ancient Ligurians.”

By the looks of it, the cult of basil is alive and well at Taverna Giulia. From the dark green waiters’ uniforms to the marble mortar-and-pestles in the window sills, the restaurant is a shrine to the herb that forms the basis of Ligurians’ most celebrated edible invention: pesto.