Looking for a 19th century abandoned mineral railroad bridge

I ignore Google's recommendation about the most convenient route as I follow a more scenic shortcut instead. It doesn't make my car's suspension happy but it definitely fills my eyes with much better views than just tarmac and concrete. Right after the village of Agios Konstantinos I'm already happily driving through an olive grove:

On the hunt for a 6th century Hellenic Christian church

I am not religiously motivated to go hunting for such stuff but if it is as old as they say (and that's 1500 years old!) then that's enough motivation already. Besides, let's be honest, can you regret a route like this?

19th century mining site

WWII fortifications SE of Athens

Abandoned marble quarry