Overlooking the Amstel canal in Amsterdam is a building with a plain gray facade, which upon closer inspection, is marked with strange reddish-brown symbols that are said to be the bloody handiwork of a mad ambassador who once lived in the house.
The tall, stark house at 216 Amstel, in the heart Amsterdam, was originally built in the early 1670s for soap manufacturer and businessman, Gijsbert Dumber, although the original owner is hardly remembered today. Although it is sometime known as the Gijsbert Dumber Huis, it is far better known as the "The House with The Blood Stains" thanks to one Coenraad van Beuningen.
van Beuningen was a six-time mayor of Amsterdam, and successful ambassador by the time he moved into 216 Amstel. Unfortunately, for all of his political achievement and respect, van Beuningen's mind began to slip in his final years. It is said that van Beuningen may have suffered from bipolar disorder, but it was likely the loss of most of his fortune to recession and speculation, that tipped him over into the insanity that he suffer from until his death. At the height of this madness, van Beuningen began painting arcane Kabbalistic signs on the lined gray facade of his building. The rumor was that he was painting them in his own blood.
The marks are much faded, but can still be seen on the outside of the private residence by eagle-eyed visitors. It is is only rumored that the paint was van Beuningen's actual blood, but whether or not this is true, it certainly looks like it.