There is a certain amount of classical music in Coimbra, but not as much as one might hope. Coimbra University doesn't have a music department (main locations for studying music are Lisbon, Porto and Évora), and it's a small city of fewer than 100k people.
However, it has a significant heritage, notably linked to the convents/monasteries, and with collections in the university library. There are a number of festivals linked to the former each year - many are essential sacred choral music.
It's unfortunate that the lusophone world's premier university has a relatively narrow range of fields of study - without music being part of this, the embedded musical tradition is not really there.
As I don't live there - although I visited regularly whilst my partner was studying there, and classical music is what I seek out! - I may well be unaware of the existence of more - but the main opportunities to hear or perform classical music are elsewhere, I'm afraid.