Amfiareion temple in East Attica
Unfortunately, people pay attention to Acropolis and not to the rest of Athens temples, like Amfiareion, located near Athens. The tour there can be combined with a sea excursion and visit the ancient ports of the East Attica coast.
Amfiareion or Amphiareion is located in East Attica and its northern part, close to Oropos and Kalamos. It was founded around the 5th century, dedicated to the God Amfiaraos. Oropos is a port that even today (there is a ferry getting you there) connects Attica to Euboea (Eretria), so during that time, it was a point of rivalry between Athenians and Beotians.
Athenians during classic times finally win Oropos and they build the temple that its remains can be seen today. The place becomes actually an ancient Olympia, with Games being held there. Alexander the Great also lets them control the area, during Hellenistic times.
During Roman times, General Sulla who had previously destroyed Athens gives more autonomy to Amfiareion and Oropos area. Later Augustus passes control of the area again to Athenians.