Every year many people visit this tourist location in the United States of America. Here is some information about the Coral Castle about , but I can't tell how you how he built because no one knows. But when you look at what he was doing, you can see that part was dealing with astronomy.
Entrance is made through a gate fashioned from a single coral block weighing nine tons.
It fits within a quarter of an inch of the walls on either side and pivots through an iron rod resting on an automobile gear. The enormous block balances so perfectly on its center of gravity that a visitor can easily push it open with one finger. Modern construction engineers are at a loss to explain how such a ponderous object could have been set with such a high level of precision. Another gate, this one a great triangle, at the opposite wall, weighs three tons. In 'Brain-Storming' you are NOT allowed to exclude any idea on what has happened, and it is apparent that Ed figured out how to counter the effects of gravity.