I went fishing off a bridge in the upper keys with a friend. We decided to leave the fishing spot to return home- around 2:00AM. We took US1 (18 mile stretch) to get back to the mainland. Once we were towards the end of the stretch a few miles from reaching Florida City(Driving North), I looked to the East out into the darkness and thought to myself; "Hey out there is where that empty military building is- the one that I had the paperwork that Sheri gave me and I gave to MM." Then suddenly, I saw an enormous glow of blue-green light appear from a domed object on the ground just above the surface behind the tree line- about half a mile into the darkness. It was spectacular! It lit up a large amount of our Eastern visible sky. The light seemed artificial sort of like a welders flickery glow, but on a huge scale! I would say the dome itself was at least 100ft wide and a transparent light green color. The Blue-Green light- that emanated from the dome- spread up into the sky making a cone shape above the dome- with a width of over half a mile. It was so large that it frightened us. I had my video camera in the back seat but the battery was dead. I forgot to charge it before leaving my house! Anyway, the the whole event reminded me of what a transformer does when it blows up in the distance, but on a giant scale- lasting much longer- and was more consistent. Plus, the brilliant Blue-Green color was unforgettable. Unfortunately, we were the only car on the road at that time.Alexander LugonesMufon F.I.