It turned out to be a toilet.
German archaeologists claim that they have found the bathroom where Martin Luther had drafted his infamous Reformation of the Christian Church back in XVI century.
The bathroom made of stone is located in recently unearthed outbuilding of Luther's house in Wittenberg. Luther himself used to say he felt as though he was in a "cesspool" when he was enlightened with the idea that not only one's soul, but a person in his entirety should be considered heavenly, sacred.
It is a known fact that the founder of Lutheranism used to suffer from indigestion and had to spend many hours in the bathroom. According to Doctor Martin Treu, a theologian from Wittenberg, it was this particular bathroom constructed in 1516 that Martin Luther had been using for his needs.
It is most likely that the idea of the radical Reformation had been harvested there. It was within those four walls that the idea concerning the fact that Christianity needs to be "down to earth" had struck Martin Luther.
Luther has left his secret dairy with notes explaining his frequent battles with indigestion. However, some details still remain unclear. For instance, scientists are still unaware of what people of XVI century had used as toilet paper. Doctor Treu notes that back in the days paper used to be too rough to be used for hygiene purposes.