Rheinfels Castle construction was started in 1245 by Count Diether V of Katzenelnbogen. After expansions, it was the largest fortress in the Middle Rhein Valley between Koblenz and Mainz. It was slighted by French Revolutionary Army troops in 1797.
The main entrance to the castle complex is a tall square clock or gate tower (~1300 AD) opposite the hotel. A connecting path joins the clock tower to the remains of the living quarters of the Earls of Hessen-Darmstadt (the so-called Darmstadt Building). The Darmstadt building was designed in Tudor style with pointed gables. The connecting path was the site of the former moat of the main castle buildings; part of which is now the large cellar or basement. This large cellar was arched over in 1587-89 in two visible phases. It is the largest self-supporting vaulted cellar in Europe and has a length of 24 metres, a width and height of approximately 16 metres and can accommodate up to 400 people.
The walls are up to 4 metres thick. Previously a 200,000 litres wine barrel was constructed for storage. The cellar was renovated in 1997 and restored to its original condition and now serves as a meeting place for concerts, theater performances, and other shows.
The castle museum is located in the former castle chapel which is the only finished room of the original castle. It is accessed through an internal gate and up the path. The museum contains a model reconstruction of the castle before its destruction giving one a sense of how big the castle used to be. The medieval castle courtyard is found beyond the castle museum building (slightly uphill). This was the center of the medieval castle which contained a bakery, pharmacy, garden, brewery, well, and livestock—which would have allowed it to withstand an extended siege. Remnants of the original 13th-century plaster which was painted white can still be found on some walls.
While much of the castle is a ruin, some of the outer buildings are now a hotel and restaurant.
References:The Amphitheatre of the Three Gauls was part of the federal sanctuary of the three Gauls dedicated to the cult of Rome and Augustus celebrated by the 60 Gallic tribes when they gathered at Lugdunum (Lyon). The amphitheatre was built at the foot of the La Croix-Rousse hill at what was then the confluence of the Rhône and Saône.
Excavations have revealed a basement of three elliptical walls linked by cross-walls and a channel surrounding the oval central arena. The arena was slightly sloped, with the building"s south part supported by a now-vanished vault. The arena"s dimensions are 67,6m by 42m. This phase of the amphitheatre housed games which accompanied the imperial cult, with its low capacity (1,800 seats) being enough for delegations from the 60 Gallic tribes.
The amphitheatre was expanded at the start of the 2nd century. Two galleries were added around the old amphitheatre, raising its width from 25 metres to 105 metres and its capacity to about 20,000 seats. In so doing it made it a building open to the whole population of Lugdunum and its environs.