What are these giant shapes in Western Sahara? (Google Maps image)

[Mr. Billion]

This is a giant rough near-circle out in the middle of Nowheresville, Western Sahara. There's something that might be a building in the middle. There are other, similar shapes to the west.

About a mile to the north is a faint set of tracks that might be tire tracks, and to the south is an odd black line sort of similar to the circle, only it's a thicker meandering line that has odd ovals with lines running through them at irregular intervals. This is probably another path, and those ovals might be rest areas. It leads to a body of water to the west.

So what are those shapes? What's the point of digging (what might be) a big irregular trench around (what might be) a building?

[lynnejanet]

I have no idea what might have made those shapes (I can't think of a better word for them, because I can't figure what I'm looking at).

I agree that the large almost-circle looks like a trench, with a "bridge" across at at least one point. Just above the circle in the second image is an almost-identical smaller circle, and each of the circles inside the large circle seem to be smaller versions of the outer one. They all seem to have a straight, deep line immediate opposite the "bridge" or the part of the 'trench' that isn't completed.

The first image looks like whatever is in the second image, but filled with sand and mostly obscured.

Weird. My 8yo son puts it down to aliens.

[mizzie]

I agree with First of Two. It looks like some kind of settlement, long ago deserted and covered with sand. The lines could be roads, looking sunken due to buildings around them. Or they could be some kind of sewer system that's either caved in or was open from the start.

But then, a closer look at the line south of the first image makes me think of some kind of mining site. Did you notice that the "ovals" on the line are broken into squares? Odd.

SO thinks some kind of irrigation, which kind of makes sense, since it leads to water.

[hambubba]

The first one looks like some kind of fortification remains; possibly fenced? Two fences with a trench? The buried stuff looks like vehicles or equipment.

[Singing in the Drizzle]

Look like some type of old fortification to me as well. If I'm remembering my history right. In the early 1900s the French were fighting with the Arabs over this area.

[Johnny Slick]

I'm going to go with crop circles made by stupid aliens.

[Delta-V]

It's part of a series of fortifications constructed by Moroccan troops as part of their annexation of Western Sahara. If you look to the south, you can see the actual wall/berm that spans a good portion of the country width-wise, along with strongpoints along the wall. I'd say from the position, it's part of the 5th such wall, constructed in the mid-80's.

Given their locations behind the main wall, the two sites (amongst many others) in question are some sort of support sites for the main fortifications farther south. The western one was clearly an artillery firebase. The smaller circular berms protect towed howitzers, and you can see the inner small trench that would have accommodated the howitzer's spades as part of a firing position. The eastern site might have been a supply depot. Just a guess.

What looks like dug trenches are really raised berms - it's an optical illusion caused by the shadows and the angle the picture was taken from. Turn the image 180 degrees and it's easier to see.

[1958Fury]

I think you moved the map over too far and you're looking at Mars.

[Delta-V]

Also, they're not 'giant'. They're ~500m and ~200m across, respectively.

[Troberg]

The light is wierd. Turn it upside down and it makes more sense. My guess is that it's a small village with a fence around it to keep lifestock from wandering off, and that fence has gathered sand into low ridges. The various smaller shapes are probably remains of houses/huts.

[Richard W]

Originally Posted by Delta-V

It's part of a series of fortifications constructed by Moroccan troops as part of their annexation of Western Sahara. If you look to the south, you can see the actual wall/berm that spans a good portion of the country width-wise, along with strongpoints along the wall. I'd say from the position, it's part of the 5th such wall, constructed in the mid-80's.

This makes most sense to me. My first instincts were an ancient village, but I couldn't work out what all the small, scattered, very black (and so well defined) holes were in the raised areas.

If it's a recent fortification then they could be shell holes left by artillery - presumably from target practice by the occupiers, since they're neatly gathered in empty areas rather than being concentrated on the fortifications.

[Hans Off]

Originally Posted by Richard W

This makes most sense to me. My first instincts were an ancient village, but I couldn't work out what all the small, scattered, very black (and so well defined) holes were in the raised areas.

If it's a recent fortification then they could be shell holes left by artillery - presumably from target practice by the occupiers, since they're neatly gathered in empty areas rather than being concentrated on the fortifications.

Shell holes or boulders... It's tricky to determine!

[BlushingBride]

They're giant sand worms. Obviously.

[Richard W]

Originally Posted by Hans Off

Shell holes or boulders... It's tricky to determine!

Yes, I suppose they could just be boulders. Originally I thought they were concentrated on the high ground to the east of the remains of the structure, and didn't appear on similar high ground a bit further away, but on closer inspection that might just be because the lighting is different on the further tiles and so they're not as obvious.

[Delta-V]

Originally Posted by Richard W

Yes, I suppose they could just be boulders. Originally I thought they were concentrated on the high ground to the east of the remains of the structure, and didn't appear on similar high ground a bit further away, but on closer inspection that might just be because the lighting is different on the further tiles and so they're not as obvious.

Remember, the black areas likely aren't depressions. They're the shadows of something standing above the surface. The picture was taken probably early morning. The shadows are well defined and extending northwest. The picture is pretty sharp, without heat haze, so that also suggests early morning. If you look at pictures of that part of the Sahara, there are rocky outcroppings all over the place.

I'd discount shell holes. For one, they're on the wrong side of the berm...one generally practices and registers artillery on the far side of the defensive line. Secondly, shell holes aren't that deep. They're either firing into loose sand, which will slide back in, or into rock, which won't make much of a hole. Plus it's got 15-20 years to refill with sand.

[Nick Theodorakis]

Originally Posted by BlushingBride

They're giant sand worms. Obviously.

You hate 'em right? I hate 'em myself!

Nick

[LittleDuck]

My dad was stationed in Morocco/Western Sahara while in the Navy, in the 1960's (yes, I know there is no water there, have heard the Navy in the desert jokes). So I would guess this could be military or something. It's pretty desolate there but not necessarily completely deserted.

How come I can't see the image?

[ganzfeld]

Giant elephant footprints.

D'oh, now I see it.

The second one looks like an archeological excavation.