The Jostberg monastery was a branch of the Franciscan observants on a ridge of the Teutoburg Forest southwest of Bielefeld. The foundations of the late Gothic monastery church have been preserved.
In a document of the year 1483 Bishop Simon III. From Paderborn, two years earlier, believers on the Loyckhus mountains had begun to worship the sacred hermit Jodokus, the patron saint of pilgrims, in a house (domunculam). As a pilgrimage was made, the bishop allowed the construction of a chapel dedicated to Jodokus and St. Mary. By 1496 at the latest, the Bielefeld Franciscan Johannes Schrage and his brother Wessel asked Duke William of Jülich and Berg, Count of Ravensberg, to appoint Franciscans to supervise the local Jodokus cult with the help of a monastic settlement. After a rejection by the Order it came only in 1498 after the intervention of Pope Alexander VI. to found an observant monastery with takeover of the existing chapel.
In 1501, the Franciscans from Rome received permission to rebuild the monastery elsewhere on the mountain. The new building was consecrated in 1502. However, the brothers complained about the wind in the winter and lack of water in the summer, as well as the remoteness that would severely hamper the pastoral care and begging. On June 10, 1507, Pope Julius II authorized the relocation of the monastery to the city of Bielefeld, where the Franciscans had been given land on Obernstrasse. The new monastery church of St. Jodokus and Francis was consecrated in 1511.
The late Gothic monastery church is preserved in foundations at a height of up to one meter. The choir is 9.1 meters wide and 14 meters long. The church was single nave with three yokes and had a 5/8 choir closure and a total length of 24.4 meters inside measure.
The ruins of the monastery church was unearthed in 1912 at the instigation of the city of Bielefeld and 1966 by the Roman Catholic parish of St. Jodokus. Since then, the building disintegrated; Souvenir hunters had repeatedly broken pieces. Only in 1993/94 was an archaeological excavation and documentation. The restoration and partial restoration of the church ruins was completed in 2009.