Sillium belongs to the municipality Holle in the district of Hildesheim (eastern Lower Saxony, Germany).

It was built on top of a former offering stone to the pagan German deity Wodan on the 218 m high Wohldenberg, which is an elongate back of a mountain situated eastern as well as above the Nette valley.

In the upper part of the past main castle, which is not cognizable as this today anymore, is situated the 32 m high Bergfried.

Other still existing buildings and ruins are parts of the up to 2 m thick enclosing wall and also the Catholic church St. Hubertus (1731), which was constructed baroque styled and arose from the former castle chapel.

So Hermann von Wohldenberg got the Poppenburg as fief, after Conrad II, bishop of Hildesheim from 1221 – 1246, completed it as fortification.

[3] In year 1275 the earls of Wohldenberg sold their shire including the castle to bishop Otto I of Hildesheim.

Their former domicile, castle Wöltingerode near Goslar, was at this time used as a Cistercians monastery, whose monks built up a distillery there.

Other owners of this time were: After the Hildesheim Diocesan Feud (1519 to 1523) the castle and the office Wohldenberg were given to the Principality of Brunswick-Wolfenbüttel.

In 1518 he donated the still existing plague column, which is a wayside shrine called “stony Jacob”, situated sub montane.