10 days in Sithonia

Hello, we are a couple (35) no kids. We want to visit Sithonia for 10 days in August. Which beaches, camp Sites, Food markets and sights would you recomend us? We don't want to sit the whole Time in the car. Maybe you can recomend us a round tripp with the 4-5 best camp sites and beaches? We would be very happy for advices.
Thank you,
The Tripps

A few more Information about us:
We love the quite and the nature and we don't like Big Partys and crowded playgrounds with big families.
Thank you,
The Tripps