The main language spoken is Greek. While many locals speak English in the touristy areas, the English language is not as prevalent as in the Netherlands.
They use the Euro in Greece. Greece is also a part of the European Union.
A bottle of water costs between one and two Euros. Like in the Netherlands, you can’t get free tap water at public places. You can drink water from the tap in your home in Athens, but the tap water is unsafe to drink in Santorini.
The best meal was chicken souvlaki in Santorini. Chicken souvlaki is chicken and peppers on a skewer served with pita bread, french fries, cucumbers, tomatoes and tzaziki sauce. We ate at a restaurant on a cliff overlooking the water and volcanic islands!
I heard traditional Greek music all over in restaurants and shops as I explored Athens.
I really enjoyed my hike from Fira to Oia on the island of Santorini. I walked along the coast across half of the island.