Giant Starfish, Vieques, Puerto Rico

18° 8'18.49"N 65°18'8.82"W

On the eastern tip of the island of Vieques, which lies about 8 miles east of the mainland of Puerto Rico, there appears to be a giant starfish formation of some sort. Actually, there are two, with the second one a short distance to the east of the one pictured here. It seems pretty mysterious, until one considers the fact that Vieques was a 900 acre U.S. Navy target range from 1941 until 2003. If you look closely, you can see that the terrain is pock-marked with small bomb craters, and there are even two junk aircraft in the upper left corner of the photo, to simulate an enemy airfield. The "giant starfish" is most likely a naval bomb target.

Why are there giant swastikas in Roswell, NM?

33°55'53.42"N 104°42'28.79"W

Think Roswell, New Mexico, and you probably think about UFOs, not giant swastikas. Actually, they are reverse swastikas, and they were used by the pilots at Roswell Army Air Force Base for target practice during WWII. Apparently, there are at least 17 of them spread out all over a wide area of New Mexico. Some people attribute the symbols to aliens, occultists, and even ancient Native Americans, despite the fact that they are well-documented by the air force and the USGS. The Army also utilized targets shaped like circles, triangles, ships, docks, and oil tanks.
Here's a web site with pics of most of the targets, though without accurate locations.