Where did the Ekklesia meet in 400 BC? In the Agora or on the Pnyx?

By 400 BC, had the Greek Ekklesia (Assembly) moved their meetings to Pnyx hill or was it still meeting in the Agora?

Wikipedia says assemblies were being held at Pynx as early as 500 BC.

The following doesn’t seem to have the answer to your original question but it’s an excellent five-part essay on ancient Greek (particularly Athenian) government:

Wikipedia says the ekklesia met in the Agora from 508 BC to the early 5th century (i.e. some time around 500-450 BC), then moved to the Pnyx hill, with two annual meetings at the Theater of Dionysus. Then, in around 300 BC, the meetings of the ekklesia were moved to the theater.

So in 400 BC, the ekklesia would be meeting at the Pnyx hill, with two annual meetings at the Theater of Dionysus.