Is there a public restroom here?

Yes there's restroom in there ,but when place is close theres rhe portable party outside on the park

It's a very large Park if you can't reach the restroom they'll let you use it in the Parthenon building museum

Yes

Yes there is

Yes porta potties

There are half a dozen porta potties located outside the Parthenon if it is not open. Unfortunately they are not very well maintained and are quite dirty.

Portapoties outside and a restroom inside the Parthenon