What are the most convenient beaches near Athens (Greece) that are 2 hours or less to get to? All I care about is the water being clear. I.e. if I am ending a Europe trip and have 3 days to blow. Is there anything where I could fly into Athens and be on the beach in say 2 hours? It's hard to figure out Greece, because of all the islands and not doing proper Google searches.
The island of Euboea (Greek: Εύβοια, Evvia) driving-distance from Athens. Indeed, its main town Chalcis (or Chalkida) (Greek: Χαλκίδα, Halkida) is approximately 1 hour away from Athens, according to google maps. The island is scattered with beaches, some of which are quite amazing. For more inspiration, here is a top 5 list from the Greek Reporter, and here is the Visit Greece page on Chalcis. Below is a sample (marketing) image of a beach in Evia, courtesy of the Greek Reporter:
The thing with the clear waters of beaches near Athens is that most of them belong either to the Saronikos gulf or the Evoikos gulf. The first one is generally spoiled by the shipyards, the refineries, all the ships going in and out of the major port of Piraeus, and all the other industries on the bay.
The second one is not spoiled, but makes a relatively closed sea where half of the moderately wealthy Athenians keep their sea-cottages and head to every weekend. I think that the beach closest to Athens and not in the waters of these two gulfs is Psatha and Porto Germeno, two neighboring beaches.
They are in the much cleaner waters of Corinthian gulf. They are 1 hour from Athens (googlemaps). You may find families of every Balkanian ethnicity loudly barbecuing there (which is not so bad as it has a folksy aspect in it) but all in all, the waters are great there, cold and crystal clear.