Ancient Aliens

One of my favorite shows is “Ancient Aliens.” I’m a big Sci-Fi guy so this is right up my ally. I believe that there’s other life out in space. We can’t be the only ones.
Some of the stuff they say makes sense and some, you got to ask yourself, “what are they talking about.” If a stone is above a certain weight and is used in a wall, it’s too big for humans to move it, so it has to be aliens who moved it with some kind of levitation device. They have no proof of this, but it as to be.
I was one episode and they had a bunch of stones in France called The Carnac Stones (no it’s not a Rock band). It’s a bunch of rocks lined up in a couple of rows for two miles. Nobody knows why they are there. Ancient Aliens says since they could be seen from the sky, they have to be some kind of marker for aliens in their ufo’s.
Now the way  I see this, if aliens are smart enough to travel 42,000 miles from planet Zippy to Earth, I’m pretty sure they don’t need a marker to go from Italy to France. There has to be some kind of GPS system built into their ships. If not, they’re going to have a long trip back home.