The Church of the Holy Trinity (Heliga Trefaldighets Kyrka) was built in the 13th century; the earliest plans were of a monastery for an order of Franciscan monks which had settled in Arboga. Early in the 16th century Gustav Vasa started Reformation in Sweden and the monastery was opened as a church for the people of Arboga.
During renovations in the 17th century a church tower was added to the building. Among the artifacts of the church is the pulpit from 1736, beautifully carved by the royal sculptor Buchard Precht. The light fittings in brass are believed to be the largest in Sweden, possibly the whole of Scandinavia. 13th century murals are displayed on the south wall, including a depiction of the life of Saint Francis.
References: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.