Wohldenberg Castle is a hilltop ruin near Sillium in Lower Saxony, Germany. Built between 1153 and 1160 by the Counts of Wöltingerode, it sits on a former pagan worship site to Wodan and once guarded key trade routes.
The castle featured an outer and inner bailey, a 32-meter-high keep, thick defensive walls, and a chapel—later replaced by the baroque-style St. Hubertus Church (1731). It was strategically placed above the Nette Valley and controlled access to the Ambergau region.
The castle was destroyed by Henry the Lion in 1180, rebuilt, and later sold to the Bishop of Hildesheim in 1275. Over centuries, it changed hands, was used by robber knights, and suffered damage during the Thirty Years' War in 1641.
By 1800, most of the castle was dismantled. Restoration began in 1858, turning the keep into a viewing tower. The site became a popular destination and housed various institutions, including a vicarage (since 1668), youth center (since 1964), and formerly, a hotel.
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.