I was in a parking lot in north Costa Mesa Ca by the north west side of the 55 Free way and the 405 Free way,and was relieving another security guard. The guard showed me VERY LARGE lights that were blue/white slightly pulsating on the horizon in a cloud. The object looked to be over a a mile in size. It was hovering to the north of where we were and was over Santa Ana CA. The object was concealing itself in a cloud. You could see a slight outline of a saucer shaped object and counted 16 lights coming from the side / bottom of the craft like huge porthole windows. It looked to be about 3 miles away and over 1 mile in size. There were periodic flashes like a camera flash every minute or so as it hovered for about 30 minutes. 2 other co-workers came to see it also and we did not report it to our company or superiors. The reactions from every one was they weren't sure they wanted to believe what they were seeing but were excited and cursing due to the size of the object.The feelings were ominous. nervous, excited but very apprehensive due to the shear size of the craft. A co-worker attempted to take a cell phone video of it however it did not come out clear enough to see. The object just faded away in the clouds after about 30 minutes.