Adolf Fredrik Church built in 1774 is one of the most central churches in Stockhol, located just north of Hötorget. Not much has been changed on the exterior since it was built and it's still one of the most beatiful churches in Stockholm. This church is open for visitors all days.
This is one of a slew of beautiful baroque churches in inner Stockholm. I attended a fantastic Christmas choral concert here in December 2003. Great acoustics here, to go along with the classic architecture.