Ehrenbreitstein is actually not a true castle, but is instead a fortification... a huge fortification. I visited here once in the late 1960s, and very little was open to the public. Not impressed, I never went there in the late 1970s. But in 2005 I went, and it was worth it, as most of the fort is now open to see.
The first castle built here was by a nobleman named Ehrenbert around 1000, and hence the name of the castle. However, it has had other names in the past. For example, a print of Koblenz under attack in 1632 during the Thirty Years War appears to have the castle named Hermanstein. This might be due to who was controlling the fort at a given moment.
The Archbishop of Trier controlled the castle at one point, and over the years it was gradually expanded over the entire hill until it became a formidable fortress. Starved into submission by the French in 1799, it took 30,000 pounds of powder to blast the batteries and walls. The present fortress was the result of construction from 1817 by Prussia, and it later became a key element of the Prussian defense of the Rhein in the 1870s and was supposed to have been destroyed by terms of the Versailles Treaty ending World War One.
Below is a panoramic composite of Ehrenbreitstein as seen from the Deutches Eck in Koblenz.
There are several ways to get to Ehrenbreitstein, but the one that is the most fun is the sesselbahn, or chairlift. Parking for the sesselbahn is not easy, and I had to park up a back road and walk a little. But this wasn't very far.
The fortress is undergoing extensive repair and renovation, and this includes some actual excavation. The sesselbahn takes you right to one of these areas, which provides a visitor with a fascinating glimpse into the foundational structure of these fortresses.
Right, a section of foundation being excavated and restored. Arches were used to minimize the amount of construction material employed, and allowed for some flexibility in the structure. The arches were actually designed to absorb some of the shock of siege equipment.