The entry fee is only 5 Euros per person! We highly recommend that you visit the museum, prior to visiting the Acropolis itself. At the museum, you can also purchase your tickets to visit the Acropolis itself for 35 Euros.
1 hour south of Athens, along the coastal road, you can visit the Temple of Poseidon. We recommend driving down to visit the temple, and then spend the day at our favorite beach bar which is only 25 minutes into your return drive back to Athens.
Beach Anavissou is 40 minutes south of Glyfada with 4-5 nice beach bars with nice and free sun beds, and the bar just expects you to purchase coffee, soda, and/or snacks in order to use the sun beds.
The view from the top of Philopappo Hill provides an overlook of the Parthenon and Herodion Atticus theatre. Walking from here to the Acropolis Museum is usually full of people and local musicians playing live music and is one of our favorite walks in Athens.