Could it be that Corona is the Keystone?
Now with the damn pic
well fuck I can't upload pic, so heres the address instead: https://www.google.com/maps/place/Keystone+Cir,+Corona,+CA+92882,+Yhdysvallat/@33.8710336,-117.5669935,15.61z/data=!4m5!3m4!1s0x80dcc7ea09736171:0xc0e6cbf85834cfd3!8m2!3d33.8465582!4d-117.5728216?fbclid=IwAR3R2chE4mK1ROLxmNEVY2YqC2u85sg2fDRDu2p0wMMSGj_IWEek5tpYk3A