Stone commemorating the birthplace of serial murderess Maria Swanenburg

She lived from 1839 to 1915. She cared for the poor and destitute in Leiden, earning her nickname Goeie Mie (Good Mie), but she poisened scores of them in order to get the inheritance or the insurance money. She was convicted in 1885 and spent the rest of her days in the work house.
More info: en.wikipedia.org/wiki/Maria_Swanenburg