Burgau Castle was originally surrounded by a water trench which gave the name to the village Burg in der Au ('Castle in the Meadow'). The fortification was of great strategic importance against ongoing Turkish and Hungarian invasions from the East across the nearby Lafnitz river. The castle was first mentioned in 1367 as a property of the lords of Puchheim. Then the municipality and the castle were given as a feoff to the house of Neitberg before being handed over to Weikhard von Polheim. Thanks to newly built fortifications commanded by Erhard von Polheim, the invading Turks could be defied in the years 1529 and 1532. In the end, the indebted property of Burgau was given to Mathias von Trauttmannsdorff, who oppressed the local population with high socage fees. In 1704, Eastern Styria was heavily devastated by attacking Kuruz, Hungarians rebelling against the Habsburgs. The mayor saved the village by offering weapons and money to the invaders.
Today the renovated Burgau Castle houses the mayor's office, apartments and a café. The festive hall and the arcaded courtyard are used for indoor and outdoor cultural events and annual exhibitions for Christmas and Easter.
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.