Complex sentence: The Theatre of Dionysus was a major open-air theatre in Athens, built at the foot of the Acropolis and forming part of the temenos of "Dionysus Eleuthereus" ("Dioe Liberator").
Split into simpler sentences: The Theatre of Dionysus was a major open-air theatre in Athens. It was built at the foot of the Acropolis and forming part of the temenos of "Dionysus Eleuthereus" ("Dioe Liberator").