The County of Ravensberg was a historical county of the Holy Roman Empire. Its territory was in present-day eastern Westphalia, Germany, at the foot of the Osning or Teutoburg Forest.

Sparrenberg Castle, also known as the Sparrenburg, is a restored fortress in the Bielefeld-Mitte district of Bielefeld, Germany. It is situated on the Sparrenberg hill in the Teutoburg Forest and towers 60 metres (200 ft) above the city centre. Its current appearance mainly originated in the 16th and 19th century. The Sparrenburg is considered to be Bielefeld's landmark.