Octant Douro (formerly Douro41)

The N222 along the Douro is routinely called one of the best driving roads in the world, and this hotel is named for its position on it: kilometre 41, on the southern bank at Vista Alegre in Castelo de Paiva. It opened as Douro41 and now runs under the Octant name.

The architecture takes its cue from the valley's terraces. The building steps down the slope in stages, built from local schist with long runs of glass, so that the structure reads as a continuation of the hillside rather than an object placed on it. Inside it is minimal and restrained, and every one of the 61 rooms and suites is angled at the view.

Rooms are contemporary, with free-standing tubs, and split between river and mountain outlooks. There is an infinity pool on the terrace above the water, a second pool, a spa with a hydrotherapy circuit, and a gym. The restaurant is panoramic and cooks regional food. There is a marina below with berths for 26 boats, plus a games room and a kids' club, which makes this one of the more genuinely family-workable options on the river.

The geography needs stating plainly. This is on the Douro, but it is not in the Douro wine region. Castelo de Paiva sits about 40 kilometres from Porto, halfway between the city and the demarcated vineyards, and the terraced landscape people picture when they think of the Douro begins well upstream. Régua is over an hour further east, Pinhão further still. As a base for the wine country it involves long daily drives; as a river hotel within easy reach of Porto, it works well.

Porto airport is around fifty minutes.