Octant Douro sits in the hills of Castelo de Paiva, with sweeping views of the river. (The Octant Collection includes six unique properties across Portugal, from the Azores to Évora, and each is designed to reflect the character of its surroundings.) Housed in a beautifully restored building, the Douro property has been modernized with care—and with sustainability in mind—preserving the original charms while introducing a sleek, contemporary aesthetic that utilizes natural materials. With 79 rooms and suites, the hotel feels both spacious and intimate—a peaceful retreat that feels wonderfully removed from everyday life. Throughout, its understated elegance lets the dramatic Douro landscapes shine.