Good place but there is no need to pay entrance fee, everything is well seen from the hill
Nice to stop off and take a look at on your way to elsewhere. There is an entrance fee (€2.50 in October 2021) and not really any facilities on site - just a toilet. Make sure you have water if there in the day: there is very little shade.
It had sewers! It had floor and wall heating!. Impressive columns of marble (some of them). And an impressive size, as if you look attentive you will see that all the hill (and even the other side of the hill) was full of buildings.
And a citadel.
And the Acropole on the top.
Better to climb the mountain. No need to pay for tickets. The result is the same.
If you like hiking from there you can find some routes. Anyway the place is nice