important in demonstrating the evolution in attitudes towards restoration since the 17th century, both in Germany and the world. Dimensions Total length: 134 m (from the steps at the entrance to the exterior wall of the east apse) External width of the nave (with aisles): 37.62 m (from exterior wall to exterior wall) Internal width of the nave: 14 m Height of the nave at the vertex of the vaults: 33 m Height of the eastern spires: 71.20 m Height of the western spires: 65.60 m Crypt Length: east-west 35 m; north-south 46 m Height: between 6.2 m and 6.5 m Features Crypt Over the centuries, crypts developed from tiny chambers into large semi-subterranean and very articulated hall crypts, which became standard forms in Italy and Germany, sometimes extending under the transepts as well as the chancel. The monumental crypt of Speyer Cathedral, consecrated in 1041, is the largest Romanesque columned hall crypt in Europe, with an area of and a height of approx. 7 m. Forty-two groin-vaults are supported on twenty cylindrical columns with simple cushion capitals. The sandstone blocks alternate in colour between yellow and rust, a typical design of the Salian and Staufer era, and providing the context of the colour-scheme of the 19th century facade. The "architectural clarity is quite exceptional, a result of the precise execution of the base moldings and the cushion capitals, together with the emphatic system of transverse arches."(see detail below) Chapels On the southern side of the cathedral is the double chapel (Doppelkapelle) of Saint Emmeram (Saint Martin) and Saint Catherine. The concept of the double chapel was well established by the end of the 11th century, dating back to the time of Charlemagne and commonly used in imperial and Episcopal chapels. Construction of the one in Speyer already started around 1050. Saint Catherine's chapel was built on occasion of the birthday of Henry III's daughter on 25 November, named after Saint Catherine of Alexandria, one of the Fourteen Holy Helpers. In 1961 the chapel was restored to its original state as a double chapel. The two chapels on top of each other are connected through an opening in the centre. Today, Saint Emmeram is a baptistery. On the northern side of the cathedral is the chapel of Saint Afra, named after an early Christian martyr. Henry IV had the chapel built in her honour because he was born on her