Ytterby gamla kyrka, Medieval church ruins in Kungalv, Sweden

Ytterby Old Church is a ruined medieval church in Ytterby, Kungälv Municipality, Bohuslän, Sweden. Built in the 12th century in Romanesque style with a straight-ended choir, it was rebuilt in 1699 with a three-sided choir apse. The surviving stone walls stand near the Nordre River, and in the northwest corner a stone with two carved human heads is set into the masonry.

The church was built in the 1100s and dedicated to Saint Hallvard, serving as a parish center until 1870. A new church was then constructed to take over its religious functions, leaving the old structure behind.

The church was long called Sankt Halvards kyrka, dedicated to Saint Hallvard, patron saint of seafarers, because it stood near the Nordre älv and the sea. Today the Ytterby-duk, a white linen cloth embroidered with cotton thread in the late Middle Ages, is kept at Gothenburg City Museum; its Latin inscriptions address the Lamb of God and the Virgin Mary.

The ruin is not maintained, and the walls are settling because of the ground conditions, so the masonry is unstable. Visitors should keep a distance from the walls and not climb on them. The site lies near the Nordre River, lower and closer to the water than the 1870 church by the railway station.

In the northwest corner sits a stone carved with two human heads, dated to the early Middle Ages and thought to show Saint Hallvard and the woman he tried to save at the Drammenfjord, where he drowned. A local legend says the world will end when this stone reaches the ground, which the settling walls may one day cause.