A former jail houses artefacts from the dawn of photography, and provides a window onto the life of one of Portugal’s most prolific novelist, who was locked up there for adultery

Most prisons are hidden away from a city’s law-abiding citizens. Not so Porto’s 18th-century Cadeia de Relação, now the Portuguese Centre for Photography. Its solid, rectangular bulk looms above the city’s old town, a stone’s throw from the landmark Torre dos Clérigos.

After hosting the felonious and unfortunate for more than two centuries, the granite-walled jail closed its doors in 1974 on Portugal’s return to democracy. In 2000, the labyrinthine building reopened to the public as a photography exhibition centre.

Facebook Twitter Pinterest The 18th-century building overlooks Porto’s old town

Today, framed photographs hang from the walls of the old group cells on the first floor, where the pauper class of criminal were once incarcerated. On show until 3 December is a set of powerful images of contemporary prison life in Portugal, a joint project between photographers Luis Barbosa and Peter Schulthess. If the iron gates don’t serve to bring the subject home, the square food hatch in the roof of the “pigsty” cell certainly will.

On the top two floors – once home to the prison’s women and its wealthy inhabitants, respectively – are the museum’s permanent exhibitions, including, at the very top, a collection of cameras from across the ages. The vintage equipment mainly belonged to history professor and photography nut António Pedro Vicente and comprises everything from early Daguerreian antiques to dinky spy cameras hidden inside Camel cigarette packets.

Facebook Twitter Pinterest The view of Porto from the former prison. Photograph: Alamy

Also amid the cabinets of old Kodaks and Polaroids is the former cell of Camilo Castelo Branco. The famed 19th-century writer was locked up (with his married lover, the writer Ana Plácido) for adultery. His 12 months behind bars inspired several books, as well as a fine bronze sculpture of the couple in the museum’s paved entrance square. Grim though his internment certainly was, the view from his window was second to none.

As a bonus, the centre also boasts a well-lit, almost unused photography library on the second floor.

• Open 10am-12.30pm and 2pm-5pm Mon-Fri, and 2pm-5pm Sat and Sun. cpf.pt