Sankt Ols Kirke

Sankt Ols Kirke, also known as Olsker Church, is a 12th-century round church located in the village of Olsker, 4 km south of Allinge on the Danish island of Bornholm. Built in the Romanesque style and reaching three storeys high, it has from the beginning consisted of a round nave, a choir and an apse.

Source: Wikipedia