Athens is a great city to explore both by foot and by subway. Make your way to the Acropolis in the center of the city and explore the historic sites in central Athens with day or weekend pass. Walk around Plaka and explore the food and market scene. Check out Syntagma Square where the Greek Parliament meets and do some shopping nearby.
A short boat ride away sits the Cyclades island chain, home to Santorini, and a number of beautiful islands. The Cyclades have the iconic Greek island architecture of white buildings with blue roofs. Some of our favorite islands include Sifnos, Serifos, and Paros, but you can't go wrong with any option. Ferries leave from Piraeus and can be booked in advance on ferryhopper.com. There are also a number of islands south of the mainland outside of this chain accessible by ferry or plane.
The Ionian coast is short flight or a decent drive west from Athens, and includes fun locations, including Kalamata (best olives in the world), Preveza (a lively sea town), and popular islands such as Corfu and Lefkada, among others.
Greece is home to some of the oldest ruins in the world. Spread throughout the country you can find many amazing places such as Delphi, Meteora, and the Olympia Ruins. The best way to get around would be to rent a car and see the sites for yourself. But be warned, most cars are manual, unless otherwise requested at the time of booking.