Mesão Frio means Cold Big House, a curious name for a town that looks over one of the warmest wine regions in Portugal. It sits on the steep north bank of the Douro, high above the river, at the point where the valley starts to be planted with terraced vineyards in earnest. The Douro region was formally demarcated in the eighteenth century, which makes it one of the oldest regulated wine regions in the world, and the stone terraces climbing every slope are the result of centuries of back-breaking work.
The setting is dramatic. The river here is wide and slow, held behind dams that have turned the old rapids into a long, still reach, and the hills fall to it in layers of green and brown. Little white farmhouses, called quintas, stand among the vines. In autumn the grape harvest turns the slopes yellow and red, and in spring the rows of vines are bright green. In summer the valley can be fiercely hot, and the stone terraces hold the warmth long into the night.
For riders, this is the heartland of one of Portugal's best roads. The N108 follows the river along the north bank, with long, flowing bends, views across the water and surfaces that are generally good. The side roads that drop from the town to the river and climb away again are far tighter and more demanding, with hairpins, short steep sections and narrow lanes between stone walls. Traffic is usually light outside the harvest season, though you may share the road with farm vehicles and the odd tourist coach. Early mornings are the best for photography, and September and October are rich in colour but busy with harvest.
Mesão Frio has about four and a half thousand residents, so you can find fuel, bakeries, cafes and small supermarkets. Valadares, to the east, is a slightly larger place. Order a glass of local red or a tawny port at a terrace overlooking the valley, and the chances are you will not want to leave. The local cooking is robust, with roast meat, bread and strong cheese.