In this richly illustrated volume, the exterior crypt and the construction findings from the Basel Cathedral excavations of 1966 and 1973/74 are presented in their context. This reveals the shape and architectural history of the cathedral of Bishop Haito (753-836), and the Heinrich Cathedral as the cathedral of Bishop Adalbero II (1025) can be graphically reconstructed; a pre-Carolingian cathedral is also made tangible. Previously unresolved questions, such as the reconstruction of the exterior crypt, are discussed. In light of the architectural history, solutions for formal problems of the current structure emerge, such as the shape of the double crypt; the location and displacement of Queen Anna's grave, as well as other difficult-to-understand situations, are clarified. Significant artworks, such as the commemorative image of the consecration of the main altar in the ambulatory and the dragon tondo, are acknowledged.