King Gustav Vasa is buried inside the cathedral with his 3 wives but only 2 are depicted on the sarcophagus. I haven't found anything explaining why they're all buried with him or why 1 of them isn't depicted, but it's an interesting tidbit of history.
When you're ready for a fika, I definitely recommend Ofvandahls Hovkonditori at Sysslomansgatan 5. It's from the late 1800s with old style dining rooms. It has wonderful coffee and treats to enjoy!