Keila Church is the biggest medieval country church in Harju county, which was obviously established shortly after the North Estonia was occupied by Danes. In 1280 a spacious square chapel was established at "Keila hill", where today there is the chancel of the church. Fragments of the paintings at the chancel walls date possibly from this period already. The main body of the church remained unbuilt at the beginning and was obviously established at the first half of the 14th century. As the influence of the Dominican order, the main body of the church was simple unvaulted box-like building.
The church was expanded in the 15th century. First the massive west-tower was built. Three-sided ending was added to the chancel, it was re-vaulted and altar table of stone was made. In 1480 southern portal was established. In 1489 the church was vaulted and it became two-aisled, which is rather seldom in Estonian churches. The church of Keila was destroyed at the Livonian War in 1558 and the interior was stolen. It was restored in 1596.
There are several chapels in the graveyard, which have been built after 1772 due it was no longer allowed to bury inside churches.
Reference: eelk.ee
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.