540-year old debts are unheard of in this day and age; I would imagine that anyone owed money for that long would simply write it off as a loss and try not to cry themselves to sleep.
That's not the case for one German town however; Mittenwalde lent some money to Berlin in 1562 and they want it back, especially now that they have a receipt for the transaction that shows the terms of the deal, which adds up to some big figures.
When town historian Vera Schmidt was going through some files, she came across the slip of paper which details the transaction: 400 guilders, to be repaid with 6% interest added every year. When she had someone do the math, factoring in inflation and all that interest, the repayment amount comes out in the trillions of Euros.
"In 1893 there was a debate in which the document was examined and the writing was determined to be authentic," Schmidt said.
Apparently, the slip was filed away in the 60's and forgotten about, but records show that someone from Mittenwalde has demanded repayment every 50 years or so, to no avail. Because Berlin is in a massive amount of debt--about 63 million Euros, according to a financial report released in June--there's not much of a chance Mittenwalde will ever see their money. They may have to go the route Columbia House Records had to go with a 15-year old me and just chalk it up to a bad decision.