the Coral Castle 'one tiny man secretly knew anti-gravity' legend — I went looking and ugh

Modern one but it's pure ancient-tech energy so it fits here. Coral Castle, Homestead, Florida. Edward Leedskalnin, Latvian immigrant, ~5 foot tall, ~100 lbs, single-handedly quarried and sculpted 1,100+ tons of oolitic limestone into walls, a tower, furniture, a 9-ton swinging gate, the lot. Worked……