Basilica of the Fourteen Holy Helpers

The masterpiece is the product of a construction blunder. Planning began in 1735; Neumann was appointed in 1742 and the foundation stone laid in April 1743. He then discovered that Gottfried Heinrich Krohne, who held the site management, had departed from the agreed drawings and shifted the building east, so the altar could no longer stand where it belonged, on the site of the apparition under the crossing dome. Demolishing the finished outer walls was out of the question, so in 1744 Neumann designed a new interior inside the existing envelope: a sequence of interlocking ovals that pulls the vaults inward and leaves the shrine free-standing in the nave, ringed by its own space. The result is a church whose façade is late Baroque and whose interior is Rococo, consecrated in 1772, nineteen years after Neumann's death. The twin towers are 75 metres high; Leo XIII raised it to minor basilica in 1897.