Sorry, Stoo. I have been absent in answering your question. I've been rather distracted by defending myself against kindergarten insults and accusations from others. I was asked to continue an old thread on this subject matter, so I thought there'd be more open-minded interest, and my first few posts were attacked with ridiculous comments to say the least. It got me distracted. I apologize for the long wait.
First, a quick comment on the "Great Lakes pyramids". When I say that, I mean pyramidal structures. Not Giza-sized monstrosities. There are pyramidal shapes of varying heights, detected by sonar scans. They are estimated to be between 5 and 25 meters high. They're too symmetrical to be natural, but I can't give anyone more of an answer than that. All I can say is what I've said before: Take the trail-head and explore it on your own.
As for the worldwide map, I used the term "ancient" sites to separate them from what sites we consider important in modern times. By ancient, shall we say, anything medieval or earlier.
Now, there are hundreds of sites. I couldn't possibly list them all. Just start looking at a worldwide map of more prominent ones and start drawing lines between them. You'll see common degrees appear (19.5 is very common), and many are on the same latitude. When I say "grid", its not a square-grid, but rather, should I say, their alignment has symmetry, a pattern if you will. City streets aren't a perfect square-grid either but we refer to them as such. In fact, city blocks are often rectangular, but we nonetheless refer to them as a grid.
Now, I'm sure some people will say that by my insisting you choose the sites, I'm setting you up for a "see what you want to see", like seeing things in clouds. That's a cross I'm prepared to bear. If I list the sites, all I do is invite myself and this thread to be subjected to another barrage of baseless accusations and insults based upon the sites chosen. Furthermore, there's more of a "wow" factor when you make the discovery yourself. It sticks in the mind better. Me, I always preferred learning not by memorizing stuff, byt by calculating it, figuring it out. Memorizing is dangerous. You just inherit the mistakes made by those before you. Probably why I take such offense at the simple-minded insults flung at me by some of the "adults" on this forum. They think they're smart because they regurgitate what others have said, rather than deconstructing, analyzing and calculating things for themselves. I encourage you to try digging up the sites on your own and literally filling in the blanks. You might be amazed at how they line up!