1- Roermond, Limburg, 1993.
2- Roermond, Limburg, 07-07-1993.
3- Bunne, Drenthe, 13-07-1993.
4- Houthem, Limburg, 26-07-1993.
5- Houthem, Limburg, 1993.
6- Ubachsberg, Limburg, 11-07-1993.
7- Slochteren, Groningen, 1993.
2- Roermond, Limburg, 07-07-1993.
This formation was found on the west-side of the railroad of Weert-Roermond. The diameter of the large circle was approx. 8-10 metres and the smaller were approx. 4-5 metres.
3- Bunne, Drenthe, 13-07-1993.
4- Houthem, Limburg, 26-07-1993.
5- Houthem, Limburg, 1993.
6- Ubachsberg, Limburg, 11-07-1993.
7- Slochteren, Groningen, 1993.
