Our Ancient forefathers were smarter than we give them credit. Anti-gravity we tend to think of as impossible. However, magnetic fields can either be strong enough to suspend a frog, or magnetic polarities can be altered.
We know that every time the Earth flips its poles, cooling lava will orient it's magnetic bits towards the North pole. When the North pole is at Geographical North, the orientation will be towards Geographical North. When the pole is in Geographical south, the orientation will be towards geographical south. We are also learning that gravity has nothing to do with mass, but electrical currents. There were several times in Earth's past when the gravity was smaller than it presently is.
One time is recent, it is said, when the Olympic Games were inducted at Olympia (mythically, it is said, by Herakles). Humans could jump higher and faster during that time circa 800 BC than they could now. The Olympic Games was inducted to celebrate these seemingly Superhuman feats.
However, how did the Ancients ever build the megalithic structures we find around the world? The temple at Yonaguni, the Pyramids at Giza, Ba'albek, and many other sites (including Stonehenge)? Did they just use simple pulleys, A-frames, and other simple tools? Or did they use the mysterious properties of magnetism and electricity? How was the Coral Castle built and how did a thin framed man did it with only simple tools?
Simple. He used magnetic levitation. We do it expensively in physics labs, however he did it inexpensively, proving that you can create a megalithic structure by simply levitating the blocks and putting it into place.
The Ancients used magnetic levitation to place all the blocks. Although there were giants in the land, to be sure, magnetic levitation was the main way of lifting multi-ton blocks and placing them precisely. They did it by changing the magnetic polarity in the stone so it would repel the Earth at a certain rate. All the ancients had was pulleys, cables (made from copper or iron, depending the availability of these ores), a teepee frame, and ropes.
The applications of Antigravity is endless. It can revolutionize the construction industry. One can use magnetic levitation to lift large concrete slabs using cheeper cranes instead of expensive ones designed to last. You can also use magnetic levitation to lift vehicles. In fact, this is already happening in the event of the maglev trains found in Germany and Japan. You can use it for airplanes as well.
Here is a special on the Coral Castle, linked from Youtube, that should explain everything.