The rectangular hill castle was the seat of the powerful counts and dukes of Jülich and had a reputation in the Middle Ages of being impregnable.

Nideggen Castle was built by the counts of Jülich in the strategically important border area of the then Herrschaft ("Lordship") of Monschau.

In 1242, after a successful battle, William IV left the then Archbishop, Conrad of Hochstaden for nine months in the dungeon of the keep.

And Conrad's successor to the throne of the Archbishopric of Cologne, Engelbert II of Falkenburg, was also held captive there by the Jülich counts for more than three years in the period from 1267 to 1271.

Hereditary disputes between the House of Cleves and Emperor Charles V over the Duchy of Geldern culminated in the Guelders Wars (also known as the Jülich feud), in the course of which the castle and town of Nideggen were destroyed by imperial artillery in 1542.

From 1901, the castle was rebuilt for the first time and used as a museum of local history, but attacks during World War II caused unprecedented damage to the building structure.

The tower house was then restored in its original form and became home to the first castle museum in North Rhine-Westphalia in 1979.

Today it is used by the Düren branch of the German Alpine Club and Nideggen Mountain Rescue Team.

The late Romanesque gate building has been the only access to the main castle since time immemorial.

After the gate had been destroyed by wars and earthquakes, it was rebuilt between 1901 and 1906 and extended with a staircase on the west side.

To be able to defend it well, its elevated entrance on the south side was well above ground level and could only be reached by ladder.

After the roof had been sold for scrap at the turn of the 18th century, the brickwork suffered great damage in the period that followed and this was not rectified until 1906.

The east flank of the palas is protected by an octagonal tower from the middle of the 14th century, whose height until 1944 was still 14 metres.

The West Tower with its large windows also consists mainly of 14th century buildings and served representative purposes.

The appearance of the buildings that used to stand on the west and north side of the castle is largely unknown.

It offers a glimpse of the Eifel region, which is rich in castles, through its exhibitions which cover an area of approximately 600 square metres.

In addition, they cover regional historical topics such as the important noble families of the Eifel and the history of the Duchy of Jülich.