Helen's pension in Santorini is great place to stay in. Highly recommend it.
Helen is a great host : she gave us advice for our stay (volcano excursion, village buses,...), picked up us from the airport to the pension and is helpful.
The pension is located in Karterados. To get to Fira (the capital) it's a 30mn walk or 5mn with the bus.
It's clean and calm with a swimming pool where you can relax. Helen also serves breakfast in the morning.
In other words, I highly recommend it.
Thank you Helen for everything.