Jardins do Palácio de Cristal

The 19th-century gardens above the river that are the locals' favourite Sunday walk — peacocks roaming free, terraced lookouts over the Douro, leafy paths that empty out as soon as you leave the main lawn. Free, open until sunset, and the panoramic views are arguably better than the Clérigos tower view (and definitely quieter). Best in the late afternoon when the light comes in low across the river.