Built early in the last century in Florida by a Latvian immigrant, purportedly to impress his gal back home who'd turned down a proposal of marriage.
Ed, a 5 foot tall, 100 lb. man, built the entire complex alone and in secrecy over the course of 28 years. Some of the Oolite limestone blocks weigh many tons. As might be expected, myths have arisen around the site, some claiming Ed had gleaned wizard-like knowledge of how to balance magnetic forces and so on. Most engineers believe he did it using a system of pulleys. There are astronomical features (small holes in widely separated stones that when looked thru aligned with the north star), sculpture, a 'throne', and a massive swinging stone door that is perfectly balanced and rotates with ease.
