Yburg is more accurately called Iburg (both pronounced "aa-bourg"). The castle was first mentioned in records in 1245, but was started in the 1100s. However, its origins are quite obscure and the site may have existed for some time prior. The site was an important fort for the Markgraf von Baden and it guarded the southwest boundary of his territory. In the late 1200s the property was granted to Markgraf Roder von Rodeck as a freeholding fief.
It was destroyed during the Peasants War in 1525, but was rebuilt in 1617-18 by Georg Friedrich with more extensive fortifications. Nevertheless, these were insufficient to hold off French forces in 1689, when it was destroyed for good. The castle may have originally been two separate forts, one an upper and the other a lower castle, but the lower may have been soon abandoned.
The tower, situated on the western side of the site, was 8.2 meters across, and with walls around 2.6 meters thick. It once stood 20 meters high, with its entrance halfway up. The eastern tower is by and large no longer extant, though there are remnants of it still visible. It was once 22 meters high.
These photos were taken in 2010.