Can thoroughly recommend Kostas Villa Maria. It’s ideally located, real quaint with wonderful views, and Kostas is so helpful. The room we stayed in was delightful but check out the other rooms in the Villa as some have spectacular views and are on one level.
The 153 steps from the square will keep you fit ....but that’s the Greek Islands!
Just loved Syros. Don’t be afraid to rent a scooter/ car and explore the rest of the island. Amazing beaches especially our favourite Galissas.