PISA, Italy — A linguine away from the Leaning Tower of Pisa’s ’hood stands another landmark. Not leaning. The Carrara Mountains.

Northern Tuscany’s 6,000 snowy-looking peaks, 650 quarries, 400 miles yield a billion tons yearly, more finest white marble than anyplace on Earth. The range dates to the Jurassic Period. So know, if redoing a john, your slab’s great-great-great ancestor was born long before Christ or your contractor.

First to hack away were first-century Romans. It produced the Pietà, the Renaissance sculpture in St. Peter’s Basilica; London’s Marble Arch; Greece’s Parthenon; DC’s Peace Monument and Michelangelo’s 16th-century masterpiece in Florence, the 14-foot statue of David.

I’m houseguesting with Shelly and Marilyn Fireman in the shadow of this wonder of the world. Restaurateur Shelly owns Fiorello’s, Trattoria Dell’Arte, Brooklyn Diner, Redeye Grill, Bond 45 and his Park Avenue South newest, Florian. The food’s delicious. He gratefully doesn’t serve one Carrara specialty that’s cured in marble containers. Lardo. Lardo’s white bacon fat. As the ancient Romans might say, “Oy.”

In Versilia, Camaiore, Viareggio, Pietrasanta along the Mediterranean and Forte dei Marmi near the mountains, Shelly, also a sculptor, visited foundries.

To gain a solid artful education

I learned historic outdoor monuments, due to climate and pollution, are often moved into museums. Outdoors, the public sees copies.

I learned the mysterious complicated mechanics of creating bronze objets d’art, which begin in research and sketching. Rarely comprised of one piece, a mold’s parts are divided. Somehow, with my Italian limited to “Pomodoro sauce,” I missed a little translation, but . . . a cast’s made. Next, a master wax-worker prepares a layer corresponding to the figure’s eventual thickness. Inside each single component of the negative mold, a craftsman spreads this layer. The form is closed. That inner core emerges after the plaster and rubber are broken. Painstaking manual finishing follows.

The wax positive is fitted with air valves and pouring channels for the liquid metal. An arduous handheld task lest the searing liquid miss a curve or indent. Then it’s what’s called realization of the refractory mold. In a blazing forge, accompanied by a hammering din, the furnace is fired for the casting.

The volcanic moment. The pouring. Heated to exact temperature, poured with steady hand lest there be bubbles and imperfections, the pouring channels fill spaces left by the lost wax.

And, behold!

Have respect. In 2012, an itsy Benvenuto Cellini doodad was insured for $68.3 million — give or take a few euro. And in the 1500s Benny did all this himself. Not even air conditioning.

Final steps

Comes the resting stage. No Subway sandwich shop assembly line, this takes forever. The object, emerging in raw nakedness, gets hand polishing, cleaning, finishing, removal of refractory waste. The final patination uses acids to obtain the artist’s color and effect.

Then, sandblasting. Chiseling with specific instruments. Elimination of all joints and fastenings required for the pouring.

Living large, craving pasta

We found Fernando Botero, famous for his stone and bronze fat ladies and prices that are just as fat, in one of the foundries. A towering supergigantic Botero figure — larger than twin elephants — filled a room.

Nice, but not exactly right as my thank you houseguest gift for Marilyn Fireman. But magnificent. No ripple, no bubble, no scratch, no seam where leg met foot or foot met toe or ear met head. Awesome. I then viewed sculptures Shelly Fireman himself made. I now have new respect. I can’t wait to order seconds on pasta in Fiorello’s.

Only in Tuscany, kids, only in Tuscany.