Kostianvirta battle was part of the Great Northern War (1700-1721). Russian army invaded to Finland in 1713 because the major Swedish army was fighting in central Europe. On October 1713, Finnish army under General Carl Gustaf Armfeldt had set the defence line to Kostianvirta river. When Russians attacked, Armfedlt’s 3,400 men first succesfully prevented 15,000 Russians to cross Kostianvirta.
On October 6, Russians made the landing coincidentally in Kostianvirta and near Mallasvesi and tried to besiege Finnish Army. Finnish soldiers were forced to withdrawn to the north. They lost 800 men and all nine cannons.
The monument of battle was erected in 1906. There are also reconstructed wooden trenches and remains of original defense structures.
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.