I am attaching three photos from Google Earth which are images of Area 51 or Groom Lake. There is an area approximately 2 miles NW of the center of the base in which 4 separate buildings each with some sort of a square "Landing Pad". Three of the "Pads" are obviously empty but one clearly has some sort of craft on it which is definitely triangular shaped.
The size of it only appears to be about ten ft. per side. Possibly something unmanned. There are no runways attached and it appears there are bunkers next to each of the pads. Since no one in Google earth had pointed these out yet and I saw no mention on your site I thought I would pass this along.
I put a marker by the pads in the photos but it is best to check it out on Google earth so you can zoom in and out. The coordinates of the "Craft" are 37 degrees 15' 44.56" North 115 degrees 50' 43.56" West
The fact that it's triangular and at Area 51 makes it worth a look.
Robert Trick