A village built on top of its own tunnels Arrive in Capistrello and you see a stone village pressed against the hillside, the Liri river below, the Roveto valley narrowing around it. What you don't see is the interesting part: two pieces of engineering, eighteen centuries apart, run under and through this mountain. Both are still there. A Roman emperor ordered the first one, to drain a lake. A 19th-century engineer designed the second, to get a train up a slope with no room to climb. Neither is a ruin you look at from a distance: one you walk into, the other is built so that anyone travelling through it never notices they did. The Emissary of Claudius, 41–52 AD Lake Fucino was the third largest lake in Italy and had no natural outlet. It rose and fell on its own, flooding the farmland around it. The emperor Claudius decided to drain it — which meant boring through Monte Salviano and carrying the water to the river Liri, which runs right past Capistrello. The works took eleven years. What came out of them is a tunnel over five kilometres long, cut by hand, with vertical shafts and service galleries so that several crews could work the same face at once. It remained the largest underground hydraulic work of the ancient world until the Fréjus tunnel, in the nineteenth century. The outlet — the Emissary itself — is at Capistrello. It is not a reconstruction. It is the stone they cut. The spiral railway, late 19th century Eighteen centuries later, a different problem. The Avezzano–Roccasecca line had to pass through the Roveto gorge, between Pescocanale and Capistrello: too much height gain in too little space, and the locomotives of the day could not manage it. The engineer Ernesto Mangiarotti, working for the Rete Mediterranea, solved it by turning the line back on itself inside the mountain. A spiral: the train goes in, completes a loop with a minimum radius of about 300 metres, and comes out higher than it went in. The gradient drops from 25 per thousand in the open to 20 inside the tunnel, which is exactly the margin that was needed. The tunnels on the spiral section have names of their own: del Molino, La Giorgia, dell'Emissario, Capistrello. And there is one detail worth the trip: people who travel through are convinced they went in a straight line. The curve is wide enough, and dark enough, that the body never registers it. How to see them The Emissary is open. You don't book, you don't need a guide, and you don't pay: you turn up and look. It is the simplest part of this whole story, and it is also why this is a place worth stopping in rather than driving past. Wear decent shoes. It is stone, and it is not a museum with handrails. The spiral railway is not something you visit — it is something you pass through. It is a working line, not an archaeological site, and the tunnel portals are visible from the valley. The right way to see it is to know it is there: next time you go through, you will know you are turning. If you are staying with us and want to know where to leave the car or which way to go in, just ask. It is quicker than looking it up. When to come Spring and autumn are the right seasons. In spring the valley is green and the water is high; in autumn the chestnut woods of the Roveto valley turn and the festivals start. Summer works because it stays cool here when the coast has stopped moving, and winter only makes sense if you pair it with snow on the Renga or the slopes at Ovindoli. Give it half a day, not an hour. The valley fills the rest.