All over the Athens Metro many of the stations feature some of the archaeological discoveries they've made while digging out the tunnels and stations. Sometimes they even have them in the same place where they found them, such as this kiln that was around when Jesus was still alive. There is however one artifact that I think could be the creepiest Subway/Metro decoration in the whole world.
At Syntagma station they have a dead guy.
Sure he's been dead a while, but it's still really creepy.
Later