A bag containing €390,000 (£316,000) was left on the Viennese bus in a bag on a seat behind the driver.
Reuters reports that the driver, referred to in reports as 'Wolfgang R', discovered the bag after inspecting his bus at the end of the line.
'Wolfgang R' told the Krone newspaper that at first he thought the bag contained "shopping or medicine", and was stunned upon opening it to discover a collection of €500 notes.
The driver then handed the huge sum of cash over to police in Vienna, who used a bank deposit slip inside the bag to trace the owner, an elderly woman.
There are no reports yet as to whether the woman decided to reward the driver for his honesty.
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