Vithisma beach may be the best bet. You can get at this by foot by taking the road out of the port, Patitiri, towards Marpounda, and turning right

(there used to be signs at the turning point for tavernas and "nice beach" at Megalo Mouria; unfortunately these have apparently gone). There is,

unbelievably, a car parking point on this track after a kilometre or so, opposite which is the path down to Vithisma. If you get to the left turn by a wall

outside a house you've gone too far. It's a steep descent (I mean it). About halfway down there's a divide in the path. It's hard to know which way to

advise: to the left, you arrive above the old beach bar but have to scramble round a 45 degree slope on your bum to get on to the beach. If you turn

right there's an even narrower path but it at leads to a set of steps: however the path just above the steps is startlingly steep (although apparently

somebody has now put a ladder there). The description of how to get there will probably explain why the beach is usually practically deserted. I get

the impression that most people nowadays arrive by boat: it is easy to hire small boats in the area and I'm sure this is the best bet.