Tower of the Winds in Plaka
I had read a bit about the Tower of the Winds, so I was keen on finding it. I found it in a stunning location, with ruins all around and the Acropolis on the hill overlooking it.
The Tower of the Winds is an octagonal Pentelic marble clocktower in the Roman Agora in Athens that functioned as a horologion or "timepiece". It is considered the world's first meteorological station. It was supposedly built by Andronicus of Cyrrhus around 50 BC, but according to other sources, might have been constructed in the 2nd century BC before the rest of the forum.