This looks like the ruins of some ancient castle . It is on the California coastline, and most of it must have been washed out to sea in centuries past. I was looking at some old maps of America, and they actually show most of California as an island; so maybe this was once part of that and was lost during an earthquake or other devastation ? In any case, it is interesting.
We have heard about the famous Nazca Lines in Peru; but there’s are also some very similar Geoglyphs in the Mojave Desert in Arizona, near the California border. Here is an article that tells more about the ones found in Arizona. https://www.rvwest.com/article/united_states/the_fascinating_mojave_desert_rock_pictures
This one is cool, largest single span stone arch bridge, and not far from where we live. I believe it still has some, limited, use. https://www.loc.gov/item/2012645656/
Here is a picture from the air of what appears to be a long flat area on top of the mountains near where the Nazca lines are located. I really think that we have had earlier civilizations which were very advanced, maybe even more so than we are, at least in some ways.
This picture is of the capitol building in Washington DC, and you can see that there is a massive amount of an older structure underneath the top part of the building. Many of these old buildings seem to have been excavated out of the dirt, and not built at the time we have been told they were built.
Are you certain that's not the White House? It was totally gutted in 1948 and a lot of basement renovations were done at that time.
Yes, I think that you are correct, @Beth Gallagher . The old crane in the picture looks about the right vintage for 1948, and that would explain why they were digging and found the old buried structures underneath the above ground part. I think that I saved the picture and just forgot that it was the White House and not the Capitol I was looking at. Somewhere I saw an old, old picture of DC and just the capitol dome was above ground, and they unearthed it, too. If I find that one again, I will post it here, too.