Having been an Istanbul visitor for 45 years (well, mainly the last 20+ years) it is astounding I had managed to never visit the Princes’ Islands (Wikipedia gives Prens Adalar and translates that to Prince Islands, but later uses the Princes’ version. Many other spellings appear if you search for them). In 2014 I made a trip, finding the boat ride by slow ferry from the Kabataş Iskele very comfortable and relaxing. I went to Bÿükada (Big Island) only, and there immediately set out for a monastery on top of a hill, that seemed to be the target for much of the other visitors. Many would rent one of the hackneys, some would rent a bike (and then ride it all over the road, preferably five abreast - or rightly decide much of the ride was too steep, and walk, bike in hand. Coming back I saw some perform great feats of speed combined with bad steering, surprisingly witnessed no accidents). I walked.
Along the road one sees several houses in a style that is not quite local, but the number of these gives the place a fine flavour. Some need a touch of paint, some are being restored. If you can stand living on an island hey musty be nice dwellings.
On top of the hill the monastery boasts being holy. I did not know this could be the case, life is full of surprises. A notice explained an icon was holy also. I paid both a visit to its church (Ayia Yorgi (St. George, in Greek: Άγιος Γεώργιος)). Had some tea nearby, and then back. A nice outing, which I may repeat with one or more of the other islands as my destination.