I have never done this walk despite the daily temptation when you drive all along this tight valley. I chose the more convenient e.g Apollonia to Kamares (walk down). The trek starts close to the bridge you pass when you come from kamares, just after...

I have posted some pics of the 20 minutes trip (only 20 minutes because I had driven just close to the access pathway!!) to Aghios Andreas. After leaving katavati, take the road to Vathy. A few kilometersa after, you catch the wooden flag on the right...