No the photo isn't from Santorini, Greece. It is from a little coastal town in Uruguay called Colonia. I took a solo day trip into the town via Buenos Aires, Argentina (I also got 4 passport stamps in one day taking a ferry between the two countries!).
It's a charming little town covered with cobblestone streets and fun colored doors (I'm a sucker for bold colored doors). The town was completely walkable and safe, and filled with cute little shops and old cars. It is definitely worth a visit if you are in Buenos Aires. My only tip would be to take the Buque Rapido ferry. I wish I had! The regular ferry ride was extremely uneventful, and I spent a good 6 hours of my day on the regular ferry, versus 2 hours total on the Buque Rapido. If you are on a time crunch or not on a strict budget (or maybe you just can't stand being on a boat/ferry) then take the Buque Rapido!