Unfinished Palace
There really is a "Palazzo Nonfinito" in Florence: Wikipedia. Alessandro Strozzi commissioned the building in 1592, but according to the legend you are about to read, it was Strozzi's ward, a mysterious young man "of wizard blood" who asked the Devil to be his architect.
The story is 1500 words long, so it will take about seven minutes to read, or about fifteen minutes if you read out loud.
Image credit: Palazzo Non Finito. Wikimedia.