Kavouri is the piece of Vouliagmeni that actually meets the sea. The beach is small, the tavernas face the water, and the houses that are worth taking are the ones where you can walk down rather than drive out. It is not a secret. On an August morning the sand fills early. It is still a different stay from a villa on a ridge with a view and a ten-minute car ride.
If you want the lake as your daily swim, stay in Vouliagmeni and visit Kavouri for dinner. If you want sand at the end of the street, stay here. Astir is around the headland, a separate beach with its own access rules, described in the beaches guide.
The villas are few. We would rather list three that are genuinely on this front than a dozen that use the name because the postcode allows it. Pool, walk time to the beach, and whether the garden is overlooked are the three facts on every proposal. The street itself is not on this page.
Voula is the next beach north if Kavouri feels too small for a week with children. The coast as a whole is in the Athens Riviera guide.