How to know the current Era ... ?

[st nickelstew]

I am new to all Civ games, have read through the forums, and have a question I haven't been able to find anywhere. Clearly, there are four eras through which your civilization progresses, and there are unique bonuses/benefits to the different civilizations in these eras.

However --and this is my question-- how does one know what era your civilization is in?? This can be strategically important if a civ (like the Greeks?) can build libraries cheaper in the 3rd era than in the 1st.

[MorteEterna]

I am new to all Civ games, have read through the forums, and have a question I haven't been able to find anywhere. Clearly, there are four eras through which your civilization progresses, and there are unique bonuses/benefits to the different civilizations in these eras.

However --and this is my question-- how does one know what era your civilization is in?? This can be strategically important if a civ (like the Greeks?) can build libraries cheaper in the 3rd era than in the 1st.

Look the roads:

white/beige: ancient
grey: medieval
red: industrial
grey/modern: modern

Whatever the game says when you join a new era.. And you will see it by the bonuses

[st nickelstew]

MorteEterna,
Thank you (!) very much for the quick response. Is there anywhere online I could have looked to find that answer, without bothering you?
Regardless, thanks again!