Trondenes Church was built by King Øystein around 1150. For ages it was the northernmost church in Christendom, and still lays claim to being Norway's northernmost medieval stone church. Originally of wood, the current stone structure replaced it around 1250 and quickly came to double as a fortification against Russian aggression. Absurdly for one of northern Norway's major cultural sights, it's often locked so do check with the tourist office.
Aside from the robust beauty of the structure itself, the church's jewels are the three finely wrought altars at the east end, all venerating Mary. Most interesting is the central one of the Virgin surrounded by her extended family with infants in arms and children tugging at skirts on all sides. Glance up too at the pair of trumpet-wielding cherubs, precariously perched atop the main pillars of the rood screen.