This temple has been built in the middle of the 4 century BC in the times when Athens reached the maximum point of its political influence. Temple dominates over the Agora of Athens and was dedicated to the Hephaestus.
This temple is very well preserved. As I know, it was only one building of antiquity in Athens which saved its columns, relief, walls and roof. When Greece become independent in the 19 century, the temple hosted first National Archeological Museum of the Greece.