A road trip through Val d'Orcia in search of undiscovered Tuscany

There's a very important question to be answered when you visit Pienza: is this the most beautiful town in Italy? I'm going to say yes. Staring at the view from the town walls is like looking at a painting. Unspooling below are hills in 50 shades of green, cut through by slashes of grey – unpaved roads chiselled from the clay beneath. Cypress avenues stripe the landscape, terracotta Renaissance towns cling to every peak. And the backdrop to it all? Monte Amiata, a dormant volcano gently wrapping around the landscape, as if she's gathering the valley in an embrace.

I'm not the only one who loves it. Pienza was the 'ideal city' for 15th-century Pope Pius II. Born in what used to be Corsignano, when he became pope he bulldozed his birthplace and created a perfectly proportioned Renaissance town in its stead. With its hulking palazzos and narrow alleyways, Pienza is still spectacular. It also produces one of Italy's best pecorino cheeses, but I must resist sampling it and move on – it's time to take a trip around the volcano, to absorb the best of Tuscany.

From Pienza, I drive towards Amiata, looping around the east side of the mountain. San Quirico d'Orcia is the first stop. Here, I stand in the shadows of ancient churches and walk through a ghostly Renaissance garden bound by tumble-down walls. Next, it's a climb towards the wine town of Montalcino then on to another winding road, Amiata's peak beckoning in the distance. Standing at the foot of a hill, centuries-old olive trees standing guard around it, is the Abbazia di Sant'Antimo, an abandoned medieval abbey.

From there, curling around more hills, through villages untouched by tourism, I reach Castiglione d'Orcia, a town balancing on a high crag over the Val d'Orcia. Pienza is visible in the distance across the valley, that famous landscape unravelling between us.

Moving around Amiata, everything changes. On its southeastern flank, green fields seem to split apart before my eyes. This is canyon country, where towns like Pitigliano teeter on ridges, the abyss either side, and roads plunge into deep gorges. At Sovana, an ancient Etruscan necropolis hides into the woods, sculpted winged daemons marking the graves. 

My final destination lies across another set of hills, in a valley where the eggy smell of sulphur curls through the window if the car. Below Saturnia – a hilltop town so nonchalant about its history that bits of Roman buildings are lined up around the war memorial in the piazza – is a volcanic lake. Warm thermal waters gush out of the source, before cleaving a hot brook through the fields.

In Roman times, soldiers came here to bathe on the way back to Rome. soothing their battle wounds in the restorative mineral waters, which simmered for 40 years underground after settling on Amiata as raindrops. Today, Terme di Saturnia is a luxury resort, and that lake beloved by the Romans is a pool. Get in and your feet still touch the clay floor before it shelves down like a crater. Bubbles fizz up from the depths, bits of plankton bobbing on top.

I go for an evening float on arrival – it's like getting into a warm bath. The next morning, I'm first in. Steam is billowing off the water into the air and paddling into the centre is like entering a cloud. All I can see is water, and all I can hear is the spring, thundering up into the crater from Amiata. It's as if time stopped when the Romans left.