These crypts or ovens as they call them are very interesting.......We visited St. Louis I cemetery and Lafayette I. They are known as wall graves and outline the cemetery as a fence. They are bought by families and are also used as temporary graves. Considering most family tombs have 2 to 4 places for crypts.....sometimes there is no room for the next deceased person so they would rent one of these wall spaces until space would become available. The remains of the individual would be removed after 1yr and 1day and be buried in the space below the grave and then someone else can now be buried there.