Athens in $470s-$580s RT

Look, ancient temples are pretty neat. So is the world's oldest weather station, built over 2,000 years ago. 

If you ask me, however, Athens' most intriguing relic is sitting in a display case at the National Archaeological Museum. Discovered in a shipwreck by sponge divers, this mysterious clockwork device has been puzzling researchers for decades.

It's called the Antikythera mechanism, and it was initially broken into about 80 pieces on the seafloor. Initially, those scattered chunks of metal were thought to be junk, until one of them cracked open to reveal something strange: tiny bronze gears.

That kind of precision clockwork was invented around 1,000 years ago. But here's the thing: the Antikythera mechanism is at least 2,000 years old.

Pieced together, the device turned out to be an astoundingly complex analog computer. Turn a small crank to input any date, and the mechanism would show you the position of the Sun, moon, stars, and planets, as well as the current lunar phase, the date of the next solar eclipse, and even the upcoming Olympic games.

Aliens? Time travelers? No one quite knows where the Antikythera mechanism came from or what it was used for, but it definitely belongs on your Athens itinerary :-)