First mention of the castle dates to the 1200s, and even by that time records indicate that the castle had two Bergfrieden, or towers, as well as two palaces.
The castle was named for Adel von Windeck around 1212. By 1347, the Margrave von Baden gained a stake in the castle, but by 1429, the Windeck family was able to regain sole possession. In the meantime, the castle burned in 1372, but was rebuilt.
The Windeck family had significant holdings in other lands, some of which they had to forsake, apparently due to financial distress. In the 1500s, Alt Windeck fell into disuse and began to be used as a quarry. By 1561 it was listed as a ruine. The last of the male line of the Windeck family died in 1592, and the property soon passed to Baden-Baden.
Monument to German war dead placed by the 143rd (later reflagged as the 343rd) Panzer Battalions, modern German Army units assigned to the 15th PzBde of the 5th Pz Div at Koblenz. This battalion was deactivated in 1992.
The southern tower (seen above) was 9.6 by 9.8 meters across, with walls from 2.5 to 3 meters thick and standing at a height of 27.6 meters. It had four stories, though one source states it had five. It's entrance was a full 15.5 meters above the ground.
The northern tower (left) was 8.5 meters across with walls around 2.6 meters and having a height of 12 meters. It had three stories.
The southeastern palas had five floors, while the northwestern had three. Some of the floors of the palases had Romanesque windows.
Special source note: the diagram contained in Krahe's "Burgen des Deutschen Mittelalters Grundriss-Lexikon" is slightly inaccurate regarding orientation, but the diagram provided at the site is worse. In the latter, the towers are shown in an east-west orientation, while in the former they are north-south. In reality, the orientation is more north-northwest-south-southeast. Thus Krahe's orientation is closest to accurate and I've used his orientation for the above description.
These photos were taken in 2010.