we noticed bright, oddly flashing lights to the south. i pulled over and we recorded on our cell phones. it was a large black triangle that flashed extremely bright white lights approx. every 3-4 seconds with mixed blues, reds, greens and yellows. the colors were more subtle and random. it would hover and list slightly and slowly rotate and it seemed to pitch sideways for a minute pr two. it was silent moving west to where we pulled over. it came within a half mile at an elevation of approx. 1000 or a bit more ft. it floated more than than it appeared tp fly as in no aerodynamical appearance as would a fixed wing aircraft. one of the edges had 2 very large, very bright lights almost like huge headlights. they would both blink on uniformally and then a blue or green, etc colored third light would also blink. the craft then changed direction going east again, but then ended up going around in a 2-3 mile circle. it seemed as if it was circling us. while ot circled when it was at its western point of the loop around us it completed, i got my closest look amd clearly could see that it was a dark triangle. anti-gravitational and silent. quite large. maybe 80-100 feet long. it banked around us and we noticed a prop airplane approaching from the sw. it had. strange twinkling lights. almost like an out of timed strobe. as it approached we clearly heard the engine and props. at that time the triangle began travelling east. away from us and the plane that flew nearly through where we had just been observing the triangle. i had seen 2 of these (i believe to be tr-3bs) on dec. 30, 2012 at 11:00 pm or so. 1 day before new years 2013. back then i was left nervous, rattled a little and excited. i caught those on camera as well. i tries filming longer but my phone seemed to freeze as if it was being jammed. that also was in el cajon. i was happy to have another experience. i hope to carry better equipment with me per chance i get another opportunity at spotting a top secret or alien craft. i believe it to be man made. but who knows. it was fascinating and wish ot lasted longer. i will submit some clips and photos from monday night aug. 31, 2020 at 9:34 pm.