Coimbra was the capital of Portugal (from 1131 to 1255). Still visible today are Roman artifacts such as the aqueduct and the cryptoporticus (a semi-subterranean gallery with vaulted ceiling). The most outstanding feature in the city is the University of Coimbra founded in 1537. It is the oldest academic institution in the Portuguese-speaking world. The campus buildings were classified as a World Heritage site by UNESCO in 2013.