Athens took 18th place and regarding to TripAdvisor «Once known for smog, traffic and tacky architecture, Athens is a city reformed thanks to fortunes brought by the 2004 Summer Olympics. Spotless parks and streets, an ultra-modern metro, new motorways, an accessible airport and all signs in perfect English make the city easily negotiable. Meriting more than a stopover en route to the islands, sophisticated Athens sites include many pillars of Western history, from the Acropolis to the Temple of Olympian Zeus, as well as treasures in the National Archaeological Museum»

Oia took 23rd place and regarding to Trip Advisor «Oia is carved out of the cliffs, and visitors can see houses built for Venetian sea captains as well as the more typical «cave houses» of the villagers. You’ll find the pure white buildings with colourful roofs that are typical of Greek architecture, and you’ll probably enjoy poking around the town. But don’t breeze through in an hour—you must stay for the sunset. It’s legendary. Watch from a café, or, better yet, from a boat—you’ll be spellbound».

GREAT!!!