Tucked away amid some of the oldest vineyards in one of the world’s most historic wine regions, Torel Quinta da Vacaria is unexpectedly modern. The boutique hotel occupies a small collection of old buildings on a historic wine estate, but architect Luís Miguel Oliveira and Studio Astolfi gave the interiors a facelift: rooms are sleek and silent with pale wood flooring, midcentury modern decor, and private balconies or terraces, many with open-air tubs. Of particular note are the hotel’s gorgeous glass-lined spa and its infinity pool and terrace, all facing the terraced hills of the Douro Valley, and its stylish dining venues, including a lively indoor-outdoor bar with panoramic views over the Douro River.