This heavy-duty Moorish gateway, just off the main shopping drag, leads through to Coimbra's upper town. Follow through the arch and head up the steep stairs known as the Rua Quebra-Costas ('Backbreaker') and you'll find yourself in the heart of the city's historic core. This labyrinthine quarter of tightly-packed houses and dark cobbled lanes was once a Moorish stronghold and for a century served as the seat of Portugal's kings.
Local legend says it was the 19th-century writer Almeida Garrett who persuaded the mayor to install the stairs.