The locations

Porto Cheli (or Porto Heli) the "Greek Riviera" is located in the eastern Peloponnese, 2 hours by car, 2 1/2 hours speed ferry cruise or 20 minutes helicopter flight from Athens. It is opposite the cosmopolitan island of Spetses and near Hydra.

It is considered one of the most prestigious resort areas in the world with a very mild climate and almost 300 days of sunshine. 

A recent article from Business Insider:

The Top Vacation Playgrounds Of The World's Super-Rich

http://www.businessinsider.com/vacation-playgrounds-of-super-rich-map-2013-10

Tasos Alexiou, a pioneer developer and the first private pilot in Greece after the war, discovered this property in the early 60's flying his plane from above. He was the first one to buy land in the area and was followed by many famous Greek VIPs but also international jet setters. 

You can look it up in Google Earth 

Latitude:  37°17'55.51"N
Longitude:  23° 8'53.89"E


Lagonisi is located approximately 30km southeast of Athens and close the Athens Airport.

Tasos Alexiou built this private housing complex in the early 90's. It consists of 6 villas with 3 autonomous residential apartments each. It is right above the sea with private access to the clear Saronic Gulf waters. It also has 2 heliports, tennis court and a helicopter hangar.

You can look it up in Google Earth 

Latitude:  37°47'39.50"N
Longitude:  23° 52'17.50"E