Burg Zelem or Zelem Castle was a knight's moated fortress located in the lowland areas left of the Rhine River between the villages Mehr and Niel in the present Gemeinde of Kranenburg.
Wikipedia https://en.wikipedia.org/wiki/Zelem_Castle
Address 15 Zelemerweg, 47559, Germany
Coordinates 51°49'6.97" N 6°1'52.844" E