Café Majestic on Rua de Santa Catarina is one of the great café interiors of southern Europe — art nouveau gilded mirrors, carved wooden panels, leather banquettes, and chandeliers filling a long, narrow room of considerable elegance. It opened in 1921 and has survived largely intact, which is not nothing given the decades Portugal spent in political and economic turmoil.
The coffee is fine, the food is adequate, and the prices are high by Porto standards. None of that is the point. Come here for the experience of sitting in a room that has been hosting Porto's literary and intellectual life for over a century, order something, and stay as long as you like. The weekday mornings are the right time — before the tourist rush and while the room still has its genuine habituée quality. The weekend brunch queue stretches down the street, which rather defeats the purpose.