Most of the time if you find a crop circle there are others nearby to be found. Crop circles seem to pop up over time in the same area too. So if you find one in GM look in LL in the same area.
The first two today came from the GE forums but looking in the same area in LL produced two more that hadn't been found before.
Artwork - Land Art/Geoglyphs 
The first two today came from the GE forums but looking in the same area in LL produced two more that hadn't been found before.