Mysterious circle in a French garden

Summary

In 1988 or early 1990, three people in Jouars-Pontchartrain (Yvelines) discovered a strange circular mark on the ground in their property. The imprint, about 2 meters in diameter, appeared to have been caused by flattened grass. The clear and defined shape of the circle was striking, especially since it remained visible for several months due to a difference in the growth of the affected grass. Although the testimony reached the GEIPAN in 2008, it was not considered useful for investigating an unidentified aerial phenomenon. There was no description of a craft, nor additional witnesses, which led to the case being classified as insufficient for further investigation.