The bus stop, in front of the Benrath Senior Centre in the western city of Düsseldorf, is an exact replica of a standard stop, with one small difference: buses never stop there.

The idea emerged after the centre was forced to rely on police to retrieve patients who wanted to return to their homes and families but had forgotten that in many cases neither existed any longer.

"If we can’t find them then we have to alert the police,” said Benrath's director Richard Neureither. “It can be particularly dangerous if this happens in winter and they spend the night out in the cold.”