We just came back from a week in Kea and visited many many beaches. Otzias Beach is easily accessible by foot and car from most parts of the island. It's located 4 km from Vourkari and 6 km from the port town of Livadi. The roads leading to it are paved and there's a few places to park even when it's busy. It's known locally as a "family beach" because of it's location and size. We went about 3 or 4 times and the busiest we found it was on a Sunday afternoon of a bank holiday weekend but even then we found space under a shady tree. It's a lovely, long sandy beach with some pebble parts on one end while the rest is sand. There are several trees for shade and also wooden cabanas placed strategically along the beach by the town council. Weekends are busier than weekdays - for obvious reasons. But it's lovely swimming and the water is nice and tranquil.
There are two nice tavernas on this beach - both of which offer exceptional food and service. One is at the bottom end of the beach and the other is at the top end. There is also a kiosk at the bottom of the beach which sells everything typical of a kiosk in Greece. Snacks, ice cream, water, refreshments, etc. And should you need an inflatable at the last minute, the kiosk has those as well.
Word to the wise - most of the islands in the Aegean (as this one is) get quite windy and gusty during August but that shouldn't stop you from visiting. Highly recommend it and well worth a visit.
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