I was scanning Latvia weeks back and found this... I have no clue what it might be. To me it almost looks like that piece of fireworks one can buy that comes in a small 5 by 5 by 5 inch box with 5 rows of 5 missiles that shoot off in crazy directions... only this whatever-it-is in Latvia is significantly larger than 5 by 5 by 5 inches!
A few kilometres ENE of Riga.
Just south of the city of Garkalne. It is available in hi-res in Google Earth...