<<The local maps mark a number of areas as being for "hobbysteinbrukken",
Signs generally read 'Hobbysteinbruck' (pl. Hobbysteinbrücke).
There's one in Solnhofen, but it's surprisingly elusive. Theoretically, you have to spend a night in the town to qualify for access. Maps are available from the hotelier, but they're very likely some years old. It's quite possible they guide you to the wrong quarry, even assuming you find the one mentioned!